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Biomedical subjects

D Georgiou

Publications and source records attributed to D Georgiou.

45 records · Page 3Linked to original sources
PubMed1992

Ultrafast CT and the cardiovascular system.

Ultrafast computed tomography (CT) is a new imaging technique that relies on electron beam technology. Its rapid image acquisition speeds make it ideal for evaluating the cardiovascular system. The high-resolution, flow, and cine-modes are unique and provide complimentary information about cardiovascular anatomy, function, and flow dynamics. Ultrafast CT can provide quantitative measurements of cardiac output, ejection fraction, ventricular volumes, and ventricular mass as well as evaluation of segmental cardiac function. This technique can be used to assess coronary artery bypass graft patency as well as to screen for coronary artery calcium. Intracardiac thrombus or tumor, valvular disease, and disorders of the pericardium can be evaluated and characterized using ultrafast CT. The diagnosis of congenital lesions of the heart and great vessels is facilitated by this imaging modality, which can help determine complex anatomic abnormalities and quantitate shunt lesions. Acquired lesions of the great vessels, such as aortic dissection and aneurysm, can be diagnosed by ultrafast CT, which can also be used for serial examination and conservative management.

Heart↗
PubMed1991

Reproducibility of left ventricular myocardial volume and mass measurements by ultrafast computed tomography.

Ultrafast computed tomography has been reported to be an accurate method of measuring left ventricular mass in dogs. To assess the interstudy, intraobserver and interobserver variability of left ventricular myocardial mass measurements in humans, left ventricular myocardial volume was measured three times within 24 h in 16 patients with ischemic heart disease. The mean percent difference of the mean of the three studies performed was -0.01 +/- 1.4% (range -2.9% to 3.6%). The regression analysis for the intraobserver variability at baseline was: Y = -4.33 + 1.03X; r = 0.99, SEE = 3.5 ml. The mean percent difference of the mean of the two sets of measurements performed by two independent observers was 0.28 +/- 2.1% (range -4.35% to 4.35%). The interobserver variability excluding papillary muscles at baseline study was: Y = -4.34 + 1.06X; r = 0.99, SEE = 1.5 ml. The regression analysis with versus without papillary muscles showed: Y = -8.72 + 0.97X; r = 0.96, SEE = 2.6 ml. Regression analysis to assess the variability of 24-h studies at end-systole versus end-diastole revealed: Y = 3.07 + 0.94X; r = 0.97, SEE = 1.8 ml. In conclusion, ultrafast computed tomography is a minimally invasive technique, with very low interstudy, intraobserver and interobserver variability for left ventricular myocardial volume and mass determinations in serial studies.

Cardiomegaly↗
PubMed1991

Left ventricular diastolic dysfunction in patients with congestive heart failure.

This study reviewed 372 male patients with congestive heart failure. Two hundred and eighty-three (77%) had congestive heart failure due to systolic dysfunction as demonstrated by radionuclide angiography. Eighty-seven (23%) with congestive heart failure were identified who had normal ejection fractions. All patients met the Framingham criteria for congestive heart failure. These 87 individuals had unrecognized diastolic heart failure. It is important to distinguish between systolic and diastolic heart failure because the pathophysiology, treatment, and prognosis differ significantly. The most frequent cause of diastolic heart failure in this study was hypertension. Diastolic dysfunction should be considered in patients with acute heart failure and severe uncontrolled hypertension, or in patients with ischemic heart disease who develop acute pulmonary edema. Patients who do not respond or deteriorate when treated for heart failure using conventional therapy may also have diastolic dysfunction. These patients warrant special recognition and tailored management.

Aged↗
PubMed1982

The interaction of alpha thalassaemia with heterozygous beta thalassaemia.

The alpha globin genotypes of 55 beta thalassaemia heterozygotes have been determined by restriction endonuclease analysis to identify those with interacting alpha thalassaemia genes. A comparison of the haematological and haemoglobin synthesis findings of individuals with normal alpha genotypes (alpha alpha/alpha alpha) with those with one (-alpha/alpha alpha) or two (-alpha/-alpha) alpha genes deleted shows that the latter two groups have more balanced globin chain synthesis ratios, higher haemoglobin levels, and larger, better haemoglobinized red cells. This suggests that the degree of globin chain imbalance is a significant factor in determining the red cell characteristics in heterozygous beta thalassaemia. Screening programmes for thalassaemia, based on the detection of low MCVs, could miss cases of the interaction of alpha and beta thalassaemia.

Chromosome Mapping↗