A hybrid 3-D reconstruction/registration algorithm for correction of head motion in emission tomography

Even with head restraint, small head movements can occur during data acquisition in emission tomography that are sufficiently large to result in detectable artifacts in the final reconstruction. Direct measurement of motion can be cumbersome and difficult to implement, whereas previous attempts to use the measured projection data for correction have been limited to simple translation orthogonal to the projection. A fully three-dimensional (3-D) algorithm is proposed that estimates the patient orientation based on the projection of motion-corrupted data, with incorporation of motion information within subsequent ordered-subset expectation-maximization subiterations. Preliminary studies have been performed using a digital version of the Hoffman brain phantom. Movement was simulated by constructing a mixed set of projections in discrete positions of the phantom. The algorithm determined the phantom orientation that best matched each constructed projection with its corresponding measured projection. In the case of a simulated single movement in 24 of 64 projections, all misaligned projections were correctly identified. Incorporating data at the determined object orientation resulted in a reduction of mean square difference (MSD) between motion-corrected and motion-free reconstructions, compared to the MSD between uncorrected and motion-free reconstructions, by a factor of 1.9

Frequency of angiotensin-converting enzyme DD genotype is decreased in patients with hypertension and left ventricular hypertrophy

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Human cardiac Kv4.3 channels are regulated by protein tyrosine kinases

Poster presentationpublished_or_final_versionThe 15th Annual Research Conference of the Department of Medicine, The University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16, suppl. 1, p. 64, abstract no. 11

Using positive youth development constructs to design a money management curriculum for junior secondary school students in Hong Kong

This paper aims to discuss the relationships between the selected positive youth development constructs and the enhancement of Hong Kong junior secondary school students' money management skills, values, and attitudes. Various issues of money management of adolescents are reviewed. These issues include the need for money management programs for adolescents, the content and coverage of an appropriate money management program, and its relationships with the selected positive youth development constructs. The curriculum units for secondary 3 students are taken as examples to illustrate the design of the program. It is believed that promoting cognitive competence, self-efficacy, and spirituality could be an effective way to enhance students' money management skills, values, and attitudes, thus preparing them better for facing the finance-related issues in life. © 2011 Patrick S. Y. Lau et al.published_or_final_versio

Incremental predictive value of vascular assessments combined with the Framingham Risk Score for prediction of coronary events in subjects of low-intermediate risk

Background: In patients with low-intermediate risk, the use of the Framingham Risk Score (FRS) may not allow accurate prediction of the occurrence of coronary events. Objective: To determine whether non-invasive vascular sonographic assessments add value to the FRS for prediction of coronary events. Methods: Brachial artery flow-mediated dilatation (FMD), carotid intima-media thickness (IMT) and the presence of carotid plaque in 70 male subjects (mean (SD) age 62 (9) years) with a low-intermediate FRS who presented with a recent coronary event were evaluated and compared with those in 35 male controls matched for age (mean age 60 (9) years). Results: Patients with a recent coronary event had a significantly higher FRS than controls. They had a significantly lower FMD (3.56 (2.41)% vs 5.18 (2.69)%, p = 0.003) and significantly higher prevalence of carotid plaque (67% vs 40%, p = 0.008), but there was no significant difference in mean maximum IMT between the two groups (1.01 (0.28) vs 0.96 (0.14) mm, p = 0.32). Multivariate analysis revealed that FMD ≤ 4.75% was an independent predictor of an acute coronary event. Of the three vascular markers, FMD ≤ 4.75% and presence of carotid plaque provided the best diagnostic accuracy for a coronary event, with area under the curve (AUC) of 0.70 and 0.64 (p = 0.001 and p = 0.033), respectively, based on receiver operating characteristic curve analysis. Furthermore, incorporating carotid plaque or FMD ≤ 4.75% into the FRS (AUC = 0.72 and AUC = 0.78) provided incremental benefit in risk stratification over FRS alone (AUC = 0.66) (p = 0.008 and p = 0.007, for comparison of difference in two receiver operating characteristic curves). Conclusions: Incorporating a measure of FMD or carotid plaque burden with FRS significantly increases the accuracy of predicting coronary events in subjects of low-intermediate risk and hence should be considered as additional investigations to improve coronary risk assessment.published_or_final_versio

PR interval prolongation in coronary patients or risk equivalent: excess risk of ischemic stroke and vascular pathophysiological insights

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Predictive value of high-sensitivity troponin-I for future adverse cardiovascular outcome in stable patients with type 2 diabetes mellitus

INTRODUCTION: High-sensitivity cardiac troponin I(hs-TnI) and T levels(hs-TnT) are sensitive biomarkers of cardiomyocyte turnover or necrosis. Prior studies of the predictive role of hs-TnT in type 2 diabetes mellitus(T2DM) patients have yielded conflicting results. This study aimed to determine whether hs-TnI, which is detectable in a higher proportion of normal subjects than hsTnT, is associated with a major adverse cardiovascular event(MACE) in T2DM patients. METHODS AND RESULTS: We compared hs-TnI level in stored serum samples from 276 consecutive patients (mean age 65 +/- 10 years; 57% male) with T2DM with that of 115 age-and sex-matched controls. All T2DM patients were prospectively followed up for at least 4 years for incidence of MACE including heart failure(HF), myocardial infarction(MI) and cardiovascular mortality. At baseline, 274(99%) patients with T2DM had detectable hs-TnI, and 57(21%) had elevated hs-TnI (male: 8.5 ng/L, female: 7.6 ng/L, above the 99th percentile in healthy controls). A total of 43 MACE occurred: HF(n = 18), MI(n = 11) and cardiovascular mortality(n = 14). Kaplan-Meier analysis showed that an elevated hs-TnI was associated with MACE, HF, MI and cardiovascular mortality. Although multivariate analysis revealed that an elevated hs-TnI independently predicted MACE, it had limited sensitivity(62.7%) and positive predictive value(38.5%). Contrary to this, a normal hs-TnI level had an excellent negative predictive value(92.2%) for future MACE in patients with T2DM. CONCLUSION: The present study demonstrates that elevated hs-TnI in patients with T2DM is associated with increased MACE, HF, MI and cardiovascular mortality. Importantly, a normal hs-TnI level has an excellent negative predictive value for future adverse cardiovascular events during long-term follow-up.published_or_final_versio

Association of subclinical myocardial injury with arterial stiffness in patients with type 2 diabetes mellitus

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PR prolongation strongly predicts new-onset myocardial infarction, ischaemic stroke, heart failure, and cardiovascular death in coronary patients or risk equivalent: a 5-year clinical-patholophysiological study

Oral PresentationOBJECTIVES: To investigate the role of PR prolongation in new-onset adverse cardiovascular (CV) events in high-risk CV patients, and the underlying pathophysiological mechanisms in terms of vascular phenotypes. METHODS: We prospectively followed up 597 high-risk CV out-patients (mean age 66±11 years; male 67%; coronary disease 55%, stroke 22%, diabetes 52%) for new-onset ischaemic stroke, myocardial infarction (MI), congestive heart failure (CHF), and CV death. Vascular phenotypes were asses…published_or_final_versio

Urotensin II in hypertension

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