Non-invasive imaging techniques, such as micro-CT or optical imaging, provide valuable information about tumour microstructure, size, volume and growth dynamics. Although histology is an approach capable of describing several of these characteristics, the invasiveness of this analysis remains a disadvantage. The main aim of this work is the methodological development of non-invasive imaging of the dynamics of tumour growth and progression. The preparation of a dual-reporter lentiviral vector enables non-invasive study of tumour growth and dissemination of metastasis. The same dual reporter will also be a part of a second vector designed as a construct for targeting mouse embryonic stem cells with aim to produce corresponding transgenic reporter mouse line. This reporter mouse line can be beneficial for future projects by providing a novel approach for studying the dynamics of tumour growth under various genetic conditions. In addition to optical imaging, this project will also include the use of micro-CT technology which, as a non-invasive approach, has the potential to provide information about the microstructure of tumour tissue in 3D that histology is not able to report.

O método mais eficaz para detecção de carcinoma mamário ductal in situ é a mamografia, que apesar de apresentar alta sensibilidade, possui baixa especificidade e não demonstra todos os casos deste tipo de lesão. Assim sendo, pesquisadores têm desenvolvido modalidades por imagem adjuntas à mamografia, das quais a mais promissora talvez seja a ressonância magnética mamária de alta resolução. Neste estudo investigou-se a capacidade da ressonância magnética, realizada em aparelho de 1,5 Tesla, com gradientes de alto desempenho, uso de bobina de superfície dedicada para mama e agente paramagnético por via endovenosa, em demonstrar focos de carcinoma ductal in situ em sua forma pura. Realizou-se análise retrospectiva em 24 pacientes que apresentaram este diagnóstico histológico e haviam sido submetidas à mamografia e à ressonância magnética. Evidenciou-se baixa reprodutibilidade entre os achados mamográficos e os da ressonância magnética mamaria, com discordância em 13 dos 24 casos (54%). Mesmo assim, concluiu-se que a ressonância magnética mamária foi valiosa, pois apesar de ter sido negativa em 5 dos 16 casos mamograficamente detectados (20,83%) revelou 8 focos de carcinoma ductal in situ não vistos à mamografia (33,33%), contribuindo de modo decisivo para o planejamento terapêutico destas pacientes. / Mammography is the most effective method to detect ductal carcinoma in situ of the breast. However, despite its high sensitivity, its specificity is low and some foci of ductal carcinoma in situ may not be detected by it. This fact has encouraged researchers to develop imaging methods adjunctive to mammography of which high resolution magnetic resonance imaging is perhaps the most promising. The purpose of this study is to investigate the ability of magnetic resonance imaging, performed in a 1.5 Tesla system with high performance gradients, the use of breast dedicated surface coil and intravenous paramagnetic agent to demonstrate foci of pure ductal carcinoma in situ. Retrospective analysis was performed to the examinations of 24 patients with this pathologic diagnosis that have been subjected to both mammography and breast magnetic resonance imaging. This study revealed that the concordance rates between mammography and magnetic resonance imaging provided low reprodutibility, being discordant in 13 of the 24 cases (54%). However, we concluded that breast magnetic resonance imaging was valuable because, despite of not depicting 5 of 16 mammographically detected cases (20,83%), it was able to detect 8 foci of ductal carcinoma in situ exclusively (33,33%), contributing to the therapeutic planning for these patients.

Hipotrofía nos músculos que estabilizam a coluna tem sido identificada nos pacientes com lombalgia. Entretanto, não se sabe se a perda muscular é causa ou conseqüência desta disfunção, nem se ela é influenciada pelo tipo de alteração discal que o indivíduo apresenta. Este estudo testou a hipótese de que a hipotrofía dos pacientes com lombalgia seja dependente do tipo de alteração discal. Para avaliar a condição muscular em diferentes tipos de alteração discal, optou-se por um estudo retrospectivo e por uma seleção aleatória de 78 exames de ressonância magnética de indivíduos com lombalgia. Em cada exame foram realizadas medidas quantitativas da porcentagem de gordura na área de secção transversa dos mm. multífidus e psoas, nos três últimos níveis da coluna lombar. A alteração discal foi encontrada em 95% dos exames, sendo o abaulamento o achado de imagem mais freqüente, seguido pela protrusão discal. A porcentagem de gordura variou conforme o tipo de alteração discal. Nos níveis com abaulamento há em ambos os músculos estudados 6% a mais de tecido gorduroso do que nos níveis onde há protrusão e esta diferença foi estatisticamente significante. Músculos nos níveis onde há protrusão sem fissura no anel fibroso apresentaram maior substituição gordurosa do que aqueles onde há protrusão com fissura. A porcentagem de gordura foi influenciada por características anatômicas como músculo estudado e nível da coluna, e por características como idade e sexo dos sujeitos. Estes resultados indicam que a hipotrofía muscular em pacientes com lombalgia não é um processo uniforme e generalizado, mas sim correlacionado a diferentes variáveis, entre elas o tipo de alteração discal que o paciente apresenta. / Low back pain patients present atrophy on muscles responsible for spine stabilization. However, it is not clear if muscle waste is related to the cause or if it is a consequence of this disfunction. Nor it is clear if muscle athophy is affected by the type of disc pathology. This study tested the hypothesis that muscle waste in low back pain patients influenced by the type of disc derangement. Magnetic resonance scans of 78 low back pain patients were randomly analysed. Cross sectional area percentage of fat tissue in multifidi and psoas major muscles was measured on the lower levels of the lumbar spine. Disc pathology was found in 95% of the exams and disc bulge was the most frequent abnormality, followed by disc protrusion. Fat percentage varied according to disc pathology and this difference was statistically significant. Muscles on levels with disc bulge presented 6% more fat deposits than muscles on levels with disc protrusion. Muscles on levels with discs without anular tear present more fat infiltration than muscles on levels with anular tear. Fat percentage was also influenced by anatomic aspects such as evaluated muscle and spine level, and sample characteristics as age and sex. The results indicated that muscle atrophy in low back pain patients is not a uniform and generalized feature. It is correlated to different variables, such as type of disc pathology

Performance of cognitive abilities, like attention, memory, language and speech, planning, decision making or logical thinking, is the basic assumption for quality of life. There are many ways how to keep and improve them. This thesis deals with connection of information technologies and cognitive sciences with focus on memory support. At the beginning there is introduced an aim of thesis in detail, in the next chapter there are described memory systems and other cognitive functions. Third chapter is focused on short introduction of brain structures, neurotransmitters affecting memory activities and imaging methods that serve for observing memory activities. In the forth chapter there are described the most common memory deficits. In the fifth part there is description of several computer programs currently used for cognitive functions support. Within the scope of practical part there was tested one software from fifth chapter with focus on memory abilities of researched sample. The results of conducted experiment are described in detail at the very end of this thesis.

O objetivo da reperfusão mecânica ou medicamentosa em pacientes com infarto agudo do miocárdio (IAM) é a restauração do fluxo sangüíneo na artéria relacionada ao infarto, a fim de limitar a necrose miocelular e preservar a função contrátil, que são os maiores preditores de sobrevida após o IAM. Entretanto, seu sucesso é indicado pela reperfusão nos capilares miocárdicos e não pela recanalização da artéria relacionada ao infarto. A ecocardiografia com perfusão miocárdica em tempo real pode ser usada para avaliar a perfusão nos capilares miocárdicos e estimar o tamanho do infarto em vários estudos experimentais. O objetivo deste estudo foi determinar a área do miocárdio infartado e sua extensão transmural pela ecocardiografia com perfusão miocárdica em tempo real, em pacientes hospitalizados nos primeiros dias após primo infarto agudo do miocárdio, tendo como padrão de referência a ressonância magnética de perfusão. Prospectivamente, foram estudados 20 pacientes (12 homens), com idade média de 64,2 ± 13,3, dentro de 12 horas de reperfusão mecânica ou medicamentosa. Os exames de ecocardiografia e ressonância magnética foram realizados do segundo ao quinto dia de infarto. O contraste \"PESDA (perfluorocarbon-exposed sonicated dextrose albumin)\" foi administrado em veia periférica, na dose de 0,1ml/Kg, em infusão contínua. A análise ecocardiográfica foi feita por uma análise qualitativa (visual) denominada escala de cinza e por uma análise quantitativa, chamada imagem paramétrica. A área de infarto média foi de 3,03 ± 2,77 cm2 para a escala de cinza (r=0,97), de 3,36 ± 2,82 cm2 para a imagem paramétrica (r= 0,99) e de 3,42 ± 2,80 cm2 para a ressonância magnética. O porcentual médio da área de infarto pela ecocardiografia em escala de cinza foi de 15,22% ± 14,84% (r= 0,97), pela imagem paramétrica foi de 16,46% ± 14,41% (r= 0,99) e pela ressonância magnética foi de 16,76% ± 14,48%. A extensão transmural do infarto em cada segmento infartado pela escala de cinza,apresentou uma correlação menor (r=0,77) em relação à imagem paramétrica (r=0,93). Em conclusão, este estudo mostrou uma excelente correlação entre ecocardiografia com perfusão miocárdica em tempo real (sobretudo pela imagem paramétrica) e ressonância magnética nas medidas da área de infarto e seu porcentual, assim como na determinação de sua extensão transmural em pacientes internados por infarto agudo do miocárdio / The aim of mechanical or pharmacological reperfusion in patients with AMI is to restore blood flow through the infarct related artery in order to limit myocellular necrosis and ultimately preserve myocardial contractile function, which is still the most powerful predictor of survival after acute myocardial infarction. The success of reperfusion, however, is indicated by perfusion of myocardial capillaries rather than simply patency of the infarct related artery. Myocardial contrast echocardiography (MCE) can be used to assess myocardial capillary perfusion and ultimately the infarct size in animals. The aim of this study was to determine by MCE the transmural extent and infarct size using magnetic resonance imaging (MRI) as a gold standard. We prospectively studied 20 patients (12 men; mean age 64.2 ± 13.3) admitted for a first acute myocardial infarction, within 12 hours after mechanical or pharmacological reperfusion. The MCE and MRI were performed between the 3rd and 5th day of acute myocardial infarction (AMI). A suspension of 0.1 ml/kg of perfluorocarbon-exposed sonicated dextrose albumin (PESDA) ultrasound contrast agent was administered as a continuous infusion. The interpretation of perfusion images by MCE was assessed by qualitative analysis (visual- VIS) and a quantitative one called parametric image (PI). The average infarct area showed by VIS was 3.03 ± 2.77 cm 2, by PI was 3.36 ± 2.82 cm 2 and by MRI was 3.42± 2.80cm 2. The average percentage of infarct area by VIS was 15.22% ± 14.84%, by PI was 16.46% ± 14.41% and by MRI was 16.76% ± 14.48%. The transmural extent was calculated in each infarcted segment by VIS, with a worse correlation (r=0,77) than PI (r=0,93). In conclusion, this study showed that MCE, in special PI, correlates well with MRI in detecting infarct size, percentage of infarct size and transmural extent in patients with acute myocardial infarction

Avaliar por ressonância magnética (IRM), placa e remodelamento coronários, comparar estenose por IRM e cinecoronariografia (CINE) e correlacionar achados de US de carótidas em pacientes (pts) com DAC. Avaliamos 10 controles(ctls) e 26 pts (lesão > 50% à CINE). Realizamos cortes transversais em artérias DA e CD (2Dblack-blood). Calculamos espessamento parietal (EP), área luminal (AL), área da parede (AP) e área total do vaso (ATV). Detectamos significantes aumentos em EP, AP e ATV nos pts vs. ctls, sem diferenças quanto a AL. Ajustando AL pela ATV, houve redução desta relação nos pts vs. ctls (remodelamento positivo). Em conclusão, a IRM identifica a parede e remodelamento de coronárias em pts com DAC, não houve correlação entre IRM e CINE quanto à estenose e placa em carótidas foi mais prevalente nos pts / To test magnetic resonance imaging (MRI) in detecting atherosclerotic plaque and coronary remodeling in patients (pts) with CAD, to compare stenosis grade (MRI vs. angiography), and to correlate carotid plaque by US and CAD. Cross-sectional slices (2D black-blood) was performed in LAD and RCA in 10 controls (ctls) and 26 pts ( > 50% stenosis) by MRI. Maximum wall thickness (WT), vessel wall area (VWA), luminal area (LA) and total vessel area (TVA) were analyzed. MRI detected increases in WT, VWA and TVA in pts vs. ctls, but not for LA. Adjusting LA for TVA, reduction was found in pts (positive remodeling). In conclusion, MRI allowed vessel abnormalities and coronary remodeling in pts with CAD, there was no correlation between stenosis grade (MRI vs. angiography) and carotid plaque was more prevalent in pts

INTRODUCTION: Patients with primary hyperparathyroidism generally have a single parathyroid adenoma that causes excessive excretion of parathyroid hormone. For about 2% to 15% of these patients, a double adenoma is present that involves one lesion on each side of the neck. CASE PRESENTATION: We describe a case of double parathyroid adenoma causing asymptomatic hypercalcemia. A presurgical technetium99m (Tc99m) sestamibi scan suggested an ipsilateral double adenoma in the left thyroid lobe. An intraoperative parathyroid hormone assay confirmed its successful removal. DISCUSSION: Although double adenomas are not yet widely acknowledged, presurgical imaging and nuclear scans can help to localize multiple lesions, and intraoperative parathyroid hormone assays can confirm the diagnosis and cure.

O objetivo do autor neste trabalho foi definir critérios pré-operatórios de invasão do seio cavernoso em imagens de Ressonância Magnética (RM) de pacientes com adenomas hipofisários. Neste estudo retrospectivo, foram revisadas as imagens de RM de 103 pacientes com adenomas hipofisários tratados cirurgicamente (48 com invasão do seio cavernoso) e compararam 8 sinais de imagem com os achados cirúrgicos (critério de referência para invasão). A análise estatística foi realizada utilizando o teste de qui-quadrado (X2), e a sensibilidade, especificidade, valor preditivo positivo(VPP) e valor preditivo negativo (VPN) foram obtidos para cada grupo de sinais. Também foram calculados, por regressão logística, os valores de \"odds ratio\" dos critérios mais significativos, e realizada a regressão logística múltipla para análise conjunta desses critérios. O seio cavernoso não estava invadido com certeza quando: a glândula hipofisária normal estava interposta entre ele e o adenoma (VPP, 100%); o compartimento venoso medial foi visibilizado (VPP, 100%); a porcentagem de envolvimento carotídeo pelo tumor foi menor que 25% (VPN, 100%) e o tumor não cruzava a linha intercarotídea medial (VPN, 100%). A invasão do seio cavernoso era certa (VPP, 100%) se: a porcentagem de envolvimento carotídeo era igual ou maior que 45%; 3 ou mais compartimentos venosos não eram visibilizados e o compartimento venoso lateral não era visibilizado. A presença de invasão era altamente sugestiva quando: o compartimento venoso inferior não era visibilizado (VPP, 92,8%); o tumor cruzava a linha intercarotídea lateral (VPP, 96,1%) e quando a parede dural lateral do seio cavernoso estava abaulada (VPP, 92,3%). Na análise conjunta, o critério com maior significância estatística para invasão foi o envolvimento carotídeo pelo adenoma > 30% / The author\'s objective in this study was to define preoperative MRI criteria of cavernous sinus invasion by pituitary adenoma. In this retrospective study, the authors reviewed the MR images of 103 patients with pituitary adenomas treated surgically (48 with cavernous sinus invasion) and compared 8 groups of MR imaging signs with the surgical findings (the standard of reference criterion for invasion). Statistical analysis was performed using a qui-square test (X2), and the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) were obtained for each group of signs. The odds ratio of the most significant criteria was also obtained and the multiple logistic regression test was used to evaluate the criteria all together. The cavernous sinus was definitely not invaded when: normal pituitary gland was interposed between the adenoma and it (PPV, 100%); the medial venous compartment was depicted (PPV, 100%); the percentage of encasement of the intracavernous internal carotid artery (ICA) was lower than 25% (NPV, 100%) and the medial intercarotid line was not crossed (NPV, 100%). Invasion of the cavernous sinus was certain (PPV, 100%) if: the percentage of encasement of the intracavernous ICA was 45% or greater and three or more venous compartment or the lateral venous compartment was not depicted. It was highly probable invaded if: the inferior venous compartment was not depicted (PPV, 92,8%); the lateral intercarotid line was crossed (PPV, 96,1%) and the lateral dural wall of the cavernous sinus was bulged (PPV, 92,3%). The most valuable criterion of cavernous sinus invasion by statistical analysis was the percentage of encasement of intracavernous ICA >30%.

INTRODUÇÃO: A hipertensão arterial pulmonar (HAP) é uma doença grave da circulação pulmonar, cuja adequada caracterização ainda depende do cateterismo cardíaco direito. A tomografia de impedância elétrica (TIE) é uma ferramenta de imagem não-invasiva que permite a estimativa a beira-leito da perfusão pulmonar através da medida da variação de impedância durante a sístole (deltaZQ). Embora a busca por métodos não-invasivos que possam descrever a HAP venha crescendo, dados a respeito da aplicação da TIE em pacientes com HAP permanecem escassos. OBJETIVOS: Avaliar a relação entre deltaZQ e perfil hemodinâmico, gravidade e prognóstico de pacientes com HAP. MÉTODOS: Pacientes acompanhados na Unidade de Circulação Pulmonar (InCor-HCFMUSP) e submetidos ao cateterismo cardíaco (por suspeita de HAP ou piora clínica) foram simultaneamente avaliados com a TIE. Foi possível medir deltaZQ por meio de acoplamento eletrocardiográfico. A variação de impedância relativa à ventilação (deltaZV) e a relação deltaZV/deltaZQ também foram analisadas. Com base nos resultados do cateterismo, os pacientes foram divididos em 2 grupos: HAP e aqueles com hemodinâmica normal, nomeados normopressóricos (NP). deltaZQ, deltaZV/deltaZQ e deltaZQ corrigido pelo parâmetro antropométrico peso (deltaZQ*p) foram comparados entre os grupos, correlacionados com parâmetros hemodinâmicos invasivos e analisados como preditores de mortalidade. RESULTADOS: Após o cateterismo, 35 pacientes compuseram o grupo HAP e 8 pacientes, o NP. Os pacientes com HAP apresentaram redução significativa de deltaZQ em comparação aos NP, bem como aumento na relação deltaZV/deltaZQ. Observou-se correlação entre deltaZQ e parâmetros hemodinâmicos, particularmente volume sistólico (VS) (r = 0,66, r2 = 0,43; p < 0,001). O parâmetro peso aumentou a correlação entre deltaZQ e VS (r = 0,77, r2 = 0,59; p < 0,001). Durante o período de estudo, 7 pacientes morreram; eles apresentavam perfil hemodinâmico pior, redução de deltaZQ comparados aos sobreviventes e uma desproporção ainda maior da relação deltaZV/deltaZQ. A sobrevida global em 36 meses foi de 65%. A sobrevida foi menor no grupo de pacientes com deltaZQ*p < 154,6% ou deltaZV/deltaZQ > 12. CONCLUSÕES: A medida de deltaZQ, particularmente corrigida pelo peso, está associada ao perfil hemodinâmico de pacientes com HAP, e sua redução, associada com gravidade de doença e pior prognóstico / BACKGROUND: Pulmonary arterial hypertension (PAH) is a severe disease of the pulmonary circulation, which still relies on the right heart catheterization (RHC) for its accurate characterization. Electrical impedance tomography (EIT) is a non-invasive image tool that allows the bedside estimation of lung perfusion through the measurement of impedance variation during systole (deltaZQ). Although the search for non-invasive methods for evaluation of PAH is developing, data concerning application of EIT in PAH patients remain scant. OBJECTIVES: To evaluate the relationship between deltaZQ and the hemodynamic profile, severity, and prognosis of PAH patients. METHODS: Patients followed at the Pulmonary Circulation Unit (InCor-HCFMUSP) and submitted to RHC (due to the suspicion of PAH or clinical worsening) were simultaneously evaluated by means of EIT. It was possible to measure deltaZQ by producing ECG-gated EIT images. The impedance variation related to ventilation (deltaZV) and the deltaZV/deltaZQ ratio were also analyzed. Based on the results of RHC, patients were discriminated into 2 groups: PAH and those with normal hemodynamics, referred as normo-pressoric (NP) group. deltaZQ, deltaZVdeltaZQ, and deltaZQ corrected by the anthropometric parameter weight (deltaZQ*w) were compared between groups, correlated to hemodynamic parameters, and analyzed as predictors of mortality. RESULTS: After RHC, 35 patients composed the PAH group, and 8 patients, the NP one. PAH patients showed a significant reduction of deltaZQ as compared to NP, as well as an increase of deltaZV/deltaZQ. A significant correlation between deltaZQ and hemodynamic parameters was found, particularly with stroke volume (SV) (r = 0.66, R2 = 0.43; p < 0.001). Weight correction increased the correlation between deltaZQ and SV (r = 0.77, R2 = 0.59; p < 0.001). During the study period, 7 patients died; they presented a worse hemodynamic profile, reduction of deltaZQ compared to PAH survivors, and an even higher deltaZV/deltaZQ ratio. The overall survival at 36 months was 65%. Patients with deltaZQ*w < 154.6 Kg.% or deltaZV/deltaZQ >12 presented worse survival. CONCLUSIONS: deltaZQ, particularly corrected by weight, is associated with hemodynamic status of PAH patients and its reduction is associated with disease severity and worse prognosis

雖然由老化引發的腦白質病變是老年人認知障礙的一個重要誘因，其機理缺並不為人所知。最新的小樣本研究表明擴散核磁造影在很大程度上是對腦白質病變最為敏感的的成像檢測手段。加深對擴散核磁造影所給出的各種指數的理解和認知對於檢測腦白質病變的病理發展以及研發試驗療法的替代標記有重要的意義。 / 為了獲得更具有臨床價值的擴散核磁造影指數，我們首先需要重構腦白質纖維束並沿著重構出的腦白質纖維束採集數值。然而，傳統的腦白質纖維束重構技術對於腦白質病變十分敏感。此外，不同病人所重構出的腦白質纖維束間缺乏映射關係也使我們無法有效進行大樣本統計分析。 / 在這個課題裡，我們提出了一個可以解決以上問題的一個全新框架。我們將專家標註過功能區的全腦白質纖維束模板配準到各個個體的腦部。此方案可自動生成個體化的全腦白質纖維束以及纖維束的功能區標註。自由形變模型被用於在全局層面對配準進行約束。所重構纖維束的曲率被用於在局部對配準進行約束。為了減輕腦白質病變對配準的影響，我們運用了一種 魯棒的主成分分析手段來檢測被病灶所干擾的纖維束。為了指導這些被干擾纖維束的配準，我們提出了一種全新的沿纖維束的區域特徵作為替代。此外，我們也探究了通過在纖維束上建立坐標系來除去離群纖維已經提供更高相關性的辦法。 / 我們所提出的框架被運用於一個腦小血管病變的臨床研究。在64個研究對象中約半數是腦白質病變患者。試驗結果證實此算法成功地將全腦白質纖維束模板配準到了所有研究對象上。沿著特定纖維束改採集的指數與認知測試分數的相關性顯著地超越了傳統指數所給出的結果。我們同時也發現沿著不同功能區腦白質纖維改採集的指數與相應的認知測試分數統計相關。 / Although age-related white matter lesion(WML)is an important substrate for cognitive impairment in the elderly, the mechanisms whereby WML induces cognitive impairment are uncertain. Recent findings based on small studies suggested that diffusion tensor imaging (DTI) measures might be the most sensitive imaging predictors in patients with WML. Understanding the imaging predictors for such disease will be useful in monitoring disease progression and in devising surrogate marker for treatment trials. / In order to obtain DTI measurements with diagnostic significance, it is first necessary to reconstruct the white-matter fiber pathways inside the brain along which certain DTI-derived values are calculated. Nevertheless, the traditional approach of white-matter tract reconstruction, or tractography, is severely hindered by the abundant existence of lesions inside the brains of WML patients. The lack of correspondence between fiber bundles across patients also makes obtaining group statistics of individual fiber bundles dicult. / In this study, we propose a novel framework that can mitigate the aforementioned issues of traditional tractography approaches. An expert-labeled whole brain tractography template is registered onto individual patients. Fiber trajectories and anatomically meaningful fiber bundles are automatically obtained by this registration. The free-form deformations are used to regularize the transformations at the whole brain level and across fiber bundles. Fiber curvatures are penalized as the intra-fiber regularization to encourage the smoothness of transformed fibers. White matter (WM) lesion is one of the major factors affecting tractography and registration of subjects with neuro Logical disorders. The Robust Principal Component Analysis(RPCA) is used to automatically detect fiber tract segments that are affected by WM lesion and a novel along-fiber regional prior is learned from healthy subjects to facilitate the registration of these fiber tract segments. We also propose to establish bundle-wise coordinate system by utilizing low-rank constraints upon the DTI measurements. The eort elevates the summary for an anatomical bundle from a scalar statistic to a vector containing changes along the representative fiber pathway. It provides means to exclude the outlier fibers while retaining partially-complete fibers. / The proposed scheme is applied to a clinical study of cerebral small vessel diseases(SVD).Experimental results show successful registration of the whole brain tractography template onto all 64 subjects, including both healthy con¬trol subjects and SVD patients. The DTI measures measured along specific registered anatomical fiber bundles exhibit significant boost in correlation with cognitive functions as compared with traditional measures. It also shows that different anatomical WM structures correlate with multiple types of cognitive functions in different ways. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / Detailed summary in vernacular field only. / He, Xiaotian. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2012. / Includes bibliographical references (leaves 46-53). / Abstracts also in Chinese. / List of Figures --- p.ix / List of Tables --- p.xii / Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- Motivation --- p.1 / Chapter 1.2 --- Our Work and Contributions --- p.2 / Chapter 1.3 --- Related Work --- p.4 / Chapter 1.4 --- Thesis Organization --- p.5 / Chapter 2 --- Background --- p.6 / Chapter 2.1 --- Background of Neuroanatomy --- p.6 / Chapter 2.2 --- Background on Diffusion Tensor Magnetic Resonance Imaging (DTMRI) --- p.11 / Chapter 3 --- Free Form Fibers --- p.18 / Chapter 3.1 --- DTI Acquisition --- p.20 / Chapter 3.2 --- Fiber Model --- p.20 / Chapter 3.3 --- Fiber-to-DTI Registration --- p.21 / Chapter 3.3.1 --- Free-Form Fibers (FFFs) --- p.21 / Chapter 3.3.2 --- Tensor-Driven Fiber-to-DTI Registration --- p.23 / Chapter 3.3.3 --- Reliability Assessment by Robust Principal Component Analysis --- p.24 / Chapter 3.3.4 --- Contextual Feature --- p.26 / Chapter 3.3.5 --- Learning the Fiber Context Prior --- p.29 / Chapter 3.3.6 --- Registration Refinement Using the Fiber Context Prior --- p.29 / Chapter 4 --- Results --- p.31 / Chapter 5 --- Future Work --- p.39 / Chapter 5.1 --- Refinement on Large Bundles --- p.39 / Chapter 5.2 --- Outlier Fiber Removal in Fiber Template --- p.40 / Chapter 6 --- Conclusion --- p.44 / Bibliography --- p.46