Thesis (M.Ph.)--Chinese University of Hong Kong. / Bibliography: leaves 66-78.

This dissertation investigated the use of a variety of multivariate statistical procedures to answer questions regarding the value of a number of medical tests and procedures in the diagnosis of space-occupying liver disease. Also investigated were some aspects of test ordering behavior by physicians. A basic methodology was developed to deal with archival data. A number of methodological problems were addressed. Discriminant function analysis was used to determine which procedures and tests served to provide the best classification of disease entities. Although the results were not spectacular, some variables, including a physical examination variable and a number of laboratory procedures were identified as being important. A more detailed analysis of the role of the laboratory variables was afforded by the use of stepwise logistic regression. In these analyses pairs of disease classifications were compared. Two of the more specific laboratory tests, total bilirubin and alkaline phosphate, entered into the equations to provide a fit to the data. Logistic regression analyses employing patient variables mirrored the results obtained with the discriminant function analyses. Liver-spleen scan indicants were also employed as predictor variables in a series of logistic regression analyses. In general, for a range of comparisons, those indicants cited in the literature as being valuable in discriminating between disease entities entered into the equations. Log-Linear models were used to investigate test ordering behavior. In general, test ordering was independent of department. The sole exception being that of the Gynecology-oncology department which relies heavily on Ultrasound. Log-Linear analyses investigating the use of a number of procedures showed differential use of procedures consistent with what is usually suggested in the medical literature for the combination of different imaging and more specialized procedures. Finally, a set of analyses investigated the ordering of a number of procedures relative to specific disease classifications. This set of analyses suffers, as do a number of the other analyses, from insufficient numbers of cases. However, some indications of differential performance of tests for different disease classifications were evident. Suggestions for further study concentrated on the development of experimental procedures given the results of this study.

by Young Lee Kei, Ricky. / Thesis (M.Phil.)--Chinese University of Hong Kong, 1998. / Includes bibliographical references (leaves 205-207). / Abstract also in Chinese. / Acknowledgements --- p.i / Statement of Originality --- p.ii / Abstract --- p.iii / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Anatomy of liver --- p.1 / Chapter 1.2 --- Anatomical Implications --- p.16 / Chapter Chapter 2 --- Background / Chapter 2.1 --- Common focal hepatic lesions --- p.21 / Chapter 2.2 --- Imaging techniques --- p.28 / Chapter 2.3 --- Characterization by sonography --- p.34 / Chapter 2.4 --- Color Power Angiography --- p.38 / Chapter Chapter 3 --- Hypothesis & Aims / Chapter 3.1 --- Hypothesis --- p.44 / Chapter 3.2 --- Aims & Objectives --- p.45 / Chapter Chapter 4 --- Material and Methods / Chapter 4.1 --- Materials --- p.47 / Chapter 4.2 --- Mode of confirmation --- p.52 / Chapter 4.3 --- Final number of subjects recruited --- p.54 / Chapter 4.4 --- Method for obtaining CD and CPA image --- p.58 / Chapter 4.5 --- Method for image analysis --- p.61 / Chapter 4.6 --- Statistical analysis --- p.68 / Chapter Chapter 5 --- Results / Chapter 5.1 --- Qualitative CD and CPA images assessment --- p.70 / Chapter 5.2 --- Interobserver qualitative analysis --- p.78 / Chapter 5.3 --- Spectral analysis --- p.84 / Chapter 5.4 --- Semi-quantitative signal parameters --- p.87 / Chapter 5.5 --- Dominance of quantified signals --- p.91 / Chapter 5.6 --- Distribution of signals in various lesions (graphical presentation) --- p.97 / Chapter 5.7 --- Penetrating vessel --- p.103 / Chapter 5.8 --- Relationship between size of lesion and quantified signal parameters --- p.104 / Chapter Chapter 6 --- Discussion / Chapter 6.1 --- Study Review --- p.109 / Chapter 6.2 --- Methods of quantitation --- p.110 / Chapter 6.3 --- Value of quantitation --- p.111 / Chapter 6.4 --- Instrumentation --- p.112 / Chapter 6.5 --- Subjects --- p.114 / Chapter 6.6 --- Image analysis --- p.115 / Chapter 6.7 --- Results --- p.117 / Chapter 6.8 --- Relationship between size and amount of signals --- p.131 / Chapter 6.9 --- Differentiation of focal hepatic lesions --- p.132 / Chapter 6.10 --- Origin of CPA signals in small hyperechoic lesions --- p.144 / Chapter 6.11 --- Limitations of CPA in focal hepatic lesion imaging --- p.146 / Chapter 6.12 --- Comparison with similar studies --- p.151 / Chapter 6.13 --- Validation of quantitation results --- p.158 / Chapter Chapter 7 --- Conclusions --- p.159 / References --- p.162 / Legends --- p.176 / Tables --- p.186 / Glossary of abbreviations --- p.193 / Selected publications relevant to thesis --- p.197 / Appendix --- p.198 / Bibliography --- p.205

Thesis (MScEng (Mechanical and Mechatronic Engineering))--University of Stellenbosch, 2009. / Percussion is a centuries old bedside diagnostic technique that is used to diagnose various conditions of the thorax and abdomen, among these, abnormalities of the liver. The physician taps the patient’s skin in the area of interest to determine the qualities or presence of the underlying tissue or organ, by listening to the generated sound. The research contained in this thesis views percussion as a system identification method which uses an impulse response to identify the underlying system. A design employing an electromagnetic actuator as input pulse generator and accelerometer as impulse response recorder was motivated and built. Tests were performed on volunteers and the recorded signals were analysed to find methods of identifying the presence of the liver from these signals. The analyses matched signals to models or simply extracted signal features and matched these model parameters or signal features to the presence of the liver. Matching was done using statistical pattern recognition methods and the true presence of the liver was established using MR images. Features extracted from test data could not be matched to the presence of the liver with sufficient confidence which led to the conclusion that either the test, apparatus or analysis was flawed. The lack of success compelled a further test on a mock-up of the problem – a silicone model with an anomaly representing the organ under test. Results from these tests showed that signals should be measured further from the actuator and the approach followed during this test could lead to the successful location of the anomaly and discrimination between subtle differences in the consistency thereof. It is concluded that further research should aim to first validate percussion as performed by the physician and increase complexity in a phased manner, validating results and apparatus at each step. The approach followed was perhaps too bold in light of the lack of fundamental understanding of percussion and the underlying mechanisms.

Made available in DSpace on 2014-08-13T14:50:49Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-01-31Bitstream added on 2014-08-13T18:00:25Z : No. of bitstreams: 1 000759968.pdf: 1004411 bytes, checksum: adb009a5e385a72cbf26e806b36a5e34 (MD5) / Avaliar a ocorrência e os fatores de risco da doença hepática gordurosa não alcoólica (DHGNA) em mulheres na pós-menopausa. Estudo clínico, transversal, envolvendo 188 mulheres na pós-menopausa (idade ≥ 45 anos e amenorréia ≥ 12 meses) acompanhadas em Ambulatório de Especialidades de Belo Horizonte de janeiro de 2011 a agosto de 2012. Critérios de não inclusão foram: doença hepática (hepatites B e C, doença colestática, insuficiência hepática e tumor); uso de drogas que afetam o metabolismo hepático; etilistas; antecedente de HIV ou câncer; e obesidade mórbida. A DHGNA foi diagnosticada por meio da ultrassonografia abdominal. Foram realizadas avaliações clínicas, antropométricas (índice de massa corpórea, IMC e circunferência da cintura, CC) e bioquímicas. Para análise estatística foram empregados os testes de t-student, distribuição Gama, Qui-Quadrado, regressão logística (odds ratio- OR). Das pacientes incluídas no presente estudo, 38,8% (73/188) apresentaram diagnóstico de esteatose hepática, sendo considerada leve em 45,2% (33/73) das pacientes, moderada em 42,5% (31/73) e, grave em 12,3% (9/73). As mulheres com DHGNA apresentaram valores pressóricos e CC elevados, e o IMC compatível com obesidade (31.5±4.5kg/m2) (p<0.05). Assim como, os valores médios de LDL, triglicerídeos, glicemia, insulina, ALT/TGP foram significativamente superiores as mulheres sem esteatose (controle) (p<0,05). Os valores médios do HOMA-IR indicaram resistência à insulina apenas no grupo com a DHGNA (6.1±4.6 vs 2.4±1.4 no controle; p<0.05). Encontrou-se diferença quanto à presença de síndrome metabólica (SM), detectada em 93.1% das mulheres com DHGNA e em 46.1% no controle (p<0.05). Em análise multivariada, ajustada para idade e peso, as variáveis consideradas de risco para o desenvolvimento da DHGNA foram: circunferência da cintura elevada (OR 1.07, IC 95% 1.01-1.13); insulinemia ... / To evaluate the prevalence and the risk factors of the nonalcoholic fatty liver disease (NAFLD) in Brazilian postmenopausal women. In this cross-sectional study, 188 women (age ≥45 years and amenorrhea ≥ 12 months) followed the Belo Horizonte Specialty Clinic from January 2011 to August 2012, were included. Exclusion criteria were: liver disease (hepatitis B and C, cholestatic disease, liver insufficiency and tumor), use of drugs that affect the liver metabolism; alcoholics; HIV or cancer history; and morbid obesity. NAFLD was diagnosed by abdominal ultrasound. Clinic, anthropometric (body mass index, BMI and waist circumference, WC) and biochemical variables were measured. The student t-test, Gamma distribution, Chisquare test and logistic regression (odds ratio-OR) were used for the statistic analysis. Of the 188 women, 38.8% had NAFLD. In 45.2% (33/73) of those patients, the steatosis was considered mild, in 42.5% (31/73) moderate and severe in 12.3% (9/73). Blood pressure, WC, BMI, LDL, triglycerides, glucose, insulin, alanine aminotransferase (AST) were significantly higher in NAFLD patients when compared without NAFLD women (control group) (p <0.05). The HOMA-IR average values showed insulin resistance only in the NAFLD group (6.1±4.6 vs 2.4±1.4 in control, p<0.05). The metabolic syndrome (MetS) was detected in 93.1% of women with NAFLD, and in 46.1% of control (p<0.05). In multivariate analysis, adjusted for for age and weight, the variables considered at risk for the development of NAFLD were: high WC (OR 1.07, 95% CI 1.01-1.13); plasma insulin (OR 1.12, 95% CI 1.05-1.19), HOMA-IR (OR 3.81, 95% CI 2.01-7.13), and presence of MetS (OR 8.68, 95% CI 3.3- 24.1). Nonalcoholic fatty liver disease showed high prevalence among Brazilian postmenopausal women. The presence of metabolic syndrome, abdominal obesity and insulin resistance were indicators of risk for the development of hepatic steatosis

Orientador: Eliana Aguiar Petri Nahas / Coorientador: Jorge Nahas Neto / Banca: Tamara Beres Lederer Goldberg / Banca: Juliana Silva Barra / Resumo: Avaliar a ocorrência e os fatores de risco da doença hepática gordurosa não alcoólica (DHGNA) em mulheres na pós-menopausa. Estudo clínico, transversal, envolvendo 188 mulheres na pós-menopausa (idade ≥ 45 anos e amenorréia ≥ 12 meses) acompanhadas em Ambulatório de Especialidades de Belo Horizonte de janeiro de 2011 a agosto de 2012. Critérios de não inclusão foram: doença hepática (hepatites B e C, doença colestática, insuficiência hepática e tumor); uso de drogas que afetam o metabolismo hepático; etilistas; antecedente de HIV ou câncer; e obesidade mórbida. A DHGNA foi diagnosticada por meio da ultrassonografia abdominal. Foram realizadas avaliações clínicas, antropométricas (índice de massa corpórea, IMC e circunferência da cintura, CC) e bioquímicas. Para análise estatística foram empregados os testes de t-student, distribuição Gama, Qui-Quadrado, regressão logística (odds ratio- OR). Das pacientes incluídas no presente estudo, 38,8% (73/188) apresentaram diagnóstico de esteatose hepática, sendo considerada leve em 45,2% (33/73) das pacientes, moderada em 42,5% (31/73) e, grave em 12,3% (9/73). As mulheres com DHGNA apresentaram valores pressóricos e CC elevados, e o IMC compatível com obesidade (31.5±4.5kg/m2) (p<0.05). Assim como, os valores médios de LDL, triglicerídeos, glicemia, insulina, ALT/TGP foram significativamente superiores as mulheres sem esteatose (controle) (p<0,05). Os valores médios do HOMA-IR indicaram resistência à insulina apenas no grupo com a DHGNA (6.1±4.6 vs 2.4±1.4 no controle; p<0.05). Encontrou-se diferença quanto à presença de síndrome metabólica (SM), detectada em 93.1% das mulheres com DHGNA e em 46.1% no controle (p<0.05). Em análise multivariada, ajustada para idade e peso, as variáveis consideradas de risco para o desenvolvimento da DHGNA foram: circunferência da cintura elevada (OR 1.07, IC 95% 1.01-1.13); insulinemia ... / Abstract: To evaluate the prevalence and the risk factors of the nonalcoholic fatty liver disease (NAFLD) in Brazilian postmenopausal women. In this cross-sectional study, 188 women (age ≥45 years and amenorrhea ≥ 12 months) followed the Belo Horizonte Specialty Clinic from January 2011 to August 2012, were included. Exclusion criteria were: liver disease (hepatitis B and C, cholestatic disease, liver insufficiency and tumor), use of drugs that affect the liver metabolism; alcoholics; HIV or cancer history; and morbid obesity. NAFLD was diagnosed by abdominal ultrasound. Clinic, anthropometric (body mass index, BMI and waist circumference, WC) and biochemical variables were measured. The student t-test, Gamma distribution, Chisquare test and logistic regression (odds ratio-OR) were used for the statistic analysis. Of the 188 women, 38.8% had NAFLD. In 45.2% (33/73) of those patients, the steatosis was considered mild, in 42.5% (31/73) moderate and severe in 12.3% (9/73). Blood pressure, WC, BMI, LDL, triglycerides, glucose, insulin, alanine aminotransferase (AST) were significantly higher in NAFLD patients when compared without NAFLD women (control group) (p <0.05). The HOMA-IR average values showed insulin resistance only in the NAFLD group (6.1±4.6 vs 2.4±1.4 in control, p<0.05). The metabolic syndrome (MetS) was detected in 93.1% of women with NAFLD, and in 46.1% of control (p<0.05). In multivariate analysis, adjusted for for age and weight, the variables considered at risk for the development of NAFLD were: high WC (OR 1.07, 95% CI 1.01-1.13); plasma insulin (OR 1.12, 95% CI 1.05-1.19), HOMA-IR (OR 3.81, 95% CI 2.01-7.13), and presence of MetS (OR 8.68, 95% CI 3.3- 24.1). Nonalcoholic fatty liver disease showed high prevalence among Brazilian postmenopausal women. The presence of metabolic syndrome, abdominal obesity and insulin resistance were indicators of risk for the development of hepatic steatosis / Mestre

Indiana University-Purdue University Indianapolis (IUPUI) / In present study, single quantum (SQ) and triple quantum filtered (TQF) 23Na magnetic resonance imaging (MRI) was used to monitor the severity and progression of CCl4 induced acute and chronic liver damage in rat model. SQ 23Na MRI was proposed to measure the 23Na signal intensity (SI) of total tissue sodium ions, and TQF 23Na MRI was proposed to measure the SI of intracellular sodium ions. In addition, shift reagent aided 23Na and 31P magnetic resonance spectroscopy (MRS) was used to measure in vivo intracellular sodium concentration ([Na+i]), total tissue sodium concentration ([Na+t]) and relative extracellular space (rECS) of liver in the same model. In acute high dose CCl4 intoxication, 24 hours after single dose of CCl4 in 5ml per kg body weight of mixture of CCl4 and oil in 1:1 ratio, SQ 23Na SI increased by 83% and TQF 23Na SI increased by 174% compared to the baseline level. According to SR-aided 23Na and 31P MRS, [Na+i] increased by 188% and [Na+t] increased by 43%. In addition, there was significant decrease in cellular energetic level, represented by ATP/Pi ratio. Histology examination showed pronounced inflammatory response in centrilobular regions, with neutrophiles infiltration, fatty accumulation and swollen hepatocytes. In chronic 8-week experiment, chronic damage was induced by biweekly administration of CCl4 in a dosage of 0.5 ml per kg body weight. From week 1 to week 6, SQ 23Na SI remained relatively constant, and then increased by 15% from week 6 to week 8. TQF 23Na SI progressively increased from week 1 to week 8, totally by 56%. Both SQ and TQF 23Na SI showed significant difference between treated group and control at every week. SR-aided 23Na and 31P MRS experiment showed that, at the end of 8-week CCl4 intoxication, both [Na+t] and rECS were higher than control, by 49% and 47% respectively; however, there was no significant difference for [Na+i] between two groups. Histology examination showed excessive deposition of extracellular matrix. In conclusion, SQ and TQF 23Na MRI appears valuable in the functional assessment of liver in noninvasive approach, and could be a promising diagnostic modality for liver diseases in clinical area.

Eighteen healthy dogs were divided into three equal groups. All dogs were evaluated at the beginning of the experiment with complete physical examination, complete blood count, serum alanine aminotransferase, serum alkaline phosphatase, serum bilirubin, serum albumin, sulfobromophthalein. excretion test, ammonia tolerance test, glucagon response test, portal and intraparenchymal pressures, operative mesenteric portography, and histologic assessment of hepatic tissue. The left hepatic vein was ligated in the chronic and acute dogs. The dogs had a ligature placed loosely around the left hepatic vein. Acute and control dogs were evaluated 24 hours postoperatively with the hematologic and biochemical tests listed above. Acute dogs were evaluated with portal and intraparenchymal pressure, operative mesenteric portography and histologic evaluation of hepatic tissue at 48 hours postoperatively. Chronic and control dogs were evaluated at 4 weeks postoperatively with all of the tests listed above. The results of all tests performed supported a transient hepatic congestion which resolved bv the fourth postoperative week. No longstanding effect on hepatic function was found. The conclusion of this experiment was that, in normal dogs, left hepatic vein ligation does not cause severe or permanent liver damage. These findings support a clinical trial of this procedure in patients with patent ductus venosus. / Master of Science

Shen, Jiayun. / Thesis (Ph.D.)--Chinese University of Hong Kong, 2013. / Includes bibliographical references (leaves 166-199). / Electronic reproduction. Hong Kong : Chinese University of Hong Kong, [2012] System requirements: Adobe Acrobat Reader. Available via World Wide Web. / Abstract also in Chinese.

The global objectives of this research are to develop a liver-specific magnetic resonance (MR) image registration and segmentation algorithms and to find highly correlated MR imaging features that help automatically score the severity of chronic liver disease (CLD). For a concise analysis of liver disease, time sequences of 3-D MR images should be preprocessed through an image registration to compensate for the patient motion, respiration, or tissue motion. To register contrast-enhanced MR image volume sequences, we propose a novel version of the demons algorithm that is based on a bi-directional local correlation coefficient (Bi-LCC) scheme. This scheme improves the speed at which a convergent sequence approaches to the optimum state and achieves the higher accuracy. Furthermore, the simple and parallelizable hierarchy of the Bi-LCC demons can be implemented on a graphics processing unit (GPU) using OpenCL. To automate segmentation of the liver parenchyma regions, an edge function-scaled region-based active contour (ESRAC), which hybridizes gradient and regional statistical information, with approximate partitions of the liver was proposed. Next, a significant purpose in grading liver disease is to assess the level of remaining liver function and to estimate regional liver function. On motion-corrected and segmented liver parenchyma regions, for quantitative analysis of the hepatic extraction of liver-specific MRI contrast agent, liver signal intensity change is evaluated from hepatobiliary phases (3-20 minutes), and parenchymal texture features are deduced from the equilibrium (3 minutes) phase. To build a classifier using texture features, a set of training input and output values, which is estimated by experts as a score of malignancy, trains the supervised learning algorithm using a multivariate normal distribution model and a maximum a posterior (MAP) decision rule. We validate the classifier by assessing the prediction accuracy with a set of testing data.