Evaluation of soft-tissue masses using segmented color Doppler velocity images: preliminary observations

OBJECTIVE

We report our initial experience with segmented color Doppler velocity-based estimates of tumor vascularity for various histogically proven soft-tissue masses.

SUBJECTS AND METHODS

Color Doppler sonography of 23 histologically proven masses in 22 patients was performed. Digital color Doppler images were acquired directly off the scanner output or from video recordings and stored on a personal computer as 24-bit gray-scale and color composite images. A color Doppler velocity segmentation and analysis algorithm was applied to the digital images, from which we calculated the normalized percentage of color Doppler area. Normalization was determined by expressing color Doppler area as a percentage of the area enclosed by a preselected region of interest. We also calculated mean percentage, SD, and cumulative distribution of color Doppler area, relative to a fixed threshold, for the acquired image data sets.

RESULTS

Estimates of mean percentage of color Doppler area showed a dynamic range of at least two or three orders of magnitude between lowest and highest values obtained. A scatterplot of mean percentage of color Doppler area versus SD of percentage of color Doppler area showed a linear monotonic relationship (r2 = .92), illustrating increasing vascular heterogeneity with mean vascularity. Preliminary data also suggest the presence of at least two distinct groups of masses (p < .0001) based on these vascularity estimates. One group corresponds to high-grade lesions in which tumor angiogenesis is expected to be important in predicting biologic behavior. The second group appeared to have little or no relationship to tumor vascularity or was of an intermediate (or lower) histologic grade.

CONCLUSION

Quantitative color Doppler estimates of tumor vascularity can be obtained over a wide dynamic range. Such estimates provide a mechanism to assess vascular heterogeneity of soft-tissue tumors. Preliminary data suggest that two biologically distinct groups of masses may be separable on the basis of quantitative velocity-based estimates of tumor vascularity as obtained from color Doppler sonography.

Dealing with diabetic nephropathy

Nephropathy may develop in patients with type 1 diabetes because poor glycemic control produces effects that eventually lead to glomerular scarring and renal failure. The worse and more prolonged the hyperglycemia, the greater the risk of diabetic nephropathy. In patients with type 2 diabetes, hyperglycemia, as well as insulin resistance and generalized vascular disease, is involved in the pathogenesis of nephropathy. The glomerular changes of early diabetic nephropathy can be identified only by renal biopsy or by testing for microalbuminuria. Once macroalbuminuria occurs (albumin excretion rate, > 300 mg/day), usually after type 1 diabetes has been present for 10 to 15 postpubertal years, end-stage renal disease is almost inevitable. However, aggressive control of hypertension in diabetic patients without microalbuminuria helps avoid nephropathy, and tight glycemic control in those with microalbuminuria can avoid or delay its onset. Even when macroalbuminuria is present, treatment can prolong renal function. Aggressive antihypertensive therapy, especially with ACE inhibitors, can reduce renal decline by half. Avoiding circumstances that may damage the kidneys (e.g., use of radiocontrast materials or nephrotoxic drugs, dehydration, hyperlipidemia, urinary tract infection, buildup of AGEs) is critical. Some treatment methods are controversial (dietary protein restriction) or still under investigation (use of injected or oral heparin) but may help delay renal transplantation or dialysis.

Weight Loss in Patients With Diabetes Treated with A Metformin-Sulfonylurea Combination in Comparison with Twice-Daily Mixed Insulin

OBJECTIVE

To investigate whether patients previously treated with insulin or sulfonylureas alone can be transferred to a combination of sulfonylureas and metformin therapy and realize a prolonged weight loss.

METHODS

We conducted a retrospective review of medical records to identify three groups of patients with type 2 diabetes: group 1, those requiring insulin who had remained on a daily regimen of two injections of mixed insulin; group 2, patients whose regimen had been changed from sulfonylureas alone to a combination of a sulfonylurea and metformin; and group 3, patients whose regimen had been converted from twice-daily mixed insulin alone to a sulfonylurea-metformin combination. Results relative to loss of weight in these three groups were analyzed.

RESULTS

For a 12-month period, no significant weight loss was noted in group 1, and group 2 showed a small nonsignificant weight loss in 6 months. Only group 3 had a significant weight loss at 3, 6, 9, and 12 months, maximizing at a mean weight loss of 22 lb (10 kg) at 12 months. In addition, in those patients in whom data were available, a significant weight loss was found at 18 and 21 months. At 21 months, however, weight began to increase. Percentage weight loss followed a pattern similar to that seen with total weight loss. The proportion of patients losing weight did not differ significantly in groups 1 and 2; however, in group 3, after 3 and 12 months a significant proportion of patients (79% and 86%, respectively) had lost weight. Race, gender, or baseline body weight had no effect on weight loss.

CONCLUSION

From this retrospective study of patients with type 2 diabetes, we conclude that conversion from insulin to combination oral therapy with sulfonylureas and metformin results in a significant weight loss for up to 21 months.

Triple Oral Antidiabetic Therapy in Type 2 Diabetes Mellitus

To determine the effectiveness of triple oral antidiabetic therapy with a sulfonylurea, a biguanide, and a thiazolidinedione, we analyzed the results in 35 patients who had previously had inadequate glycemic control with a combination of glimepiride and metformin. The study cohort consisted of 27 men and 8 women (mean age, 55.8 years) who had had type 2 diabetes mellitus for a mean duration of 8.7 years. The addition of troglitazone (600 mg/day administered with the largest meal) to the glimepiride and metformin therapy yielded normal or near-normal glycemia in all 35 patients. Glycemic control was initially associated with mean weight gain; subsequently, however, mean weight was reduced to below the baseline level--perhaps attributable to the anorectic effect of metformin. Thus, for the first time, triple oral antidiabetic therapy with glimepiride, metformin, and troglitazone has been shown to be an efficacious therapeutic option for type 2 diabetes.

Diabetic ketoacidosis. Why early detection and aggressive treatment are crucial

Diabetic ketoacidosis is a preventable condition that usually has a satisfactory outcome. However, the potential for a poor outcome and even death demands early and aggressive treatment. Insulin administration, rehydration, and electrolyte replacement are the mainstays of treatment. A search for the underlying cause is also a priority if recurrences are to be avoided.

Outcome of Metformin-Facilitated Reinitiation of Oral Diabetic Therapy in Insulin-Treated Patients with Non-Insulin-Dependent Diabetes Mellitus

OBJECTIVE

To test the feasibility of reimplementation of oral diabetic therapy in insulin-treated patients with non-insulin-dependent diabetes mellitus (NIDDM) and to determine the characteristics of patients in whom such conversion was successful.

METHODS

We attempted reinitiation of combination oral therapy with metformin and a sulfonylurea in 55 consecutive C-peptide-positive patients who had had NIDDM for less than 30 years and had received insulin therapy for less than 10 years.

RESULTS

Reinitiation of oral therapy was successful in 42 patients and unsuccessful in 13. Reinitiation of oral therapy was unsuccessful because of lack of diabetic control in nine patients and gastrointestinal side effects in four patients. The successful group had a lower insulin requirement (P = 0.004), a shorter duration of insulin therapy (P = 0.013), and a lower body mass index (P = 0.014). Baseline glycosylated hemoglobin, C-peptide level, age, and duration of diabetes were not significant predictive factors. Glycosylated hemoglobin levels were significantly lower (mean, 1.3%; P = 0.0001) after successful reinitiation of oral therapy in comparison with before. Both groups of patients (those with successful and those with unsuccessful conversion to oral therapy) lost weight.

CONCLUSION

The group of patients with NIDDM in whom reinitiation of combination oral therapy is most likely to be successful are those with a shorter duration of insulin therapy, lower insulin requirements, and lower body mass index. Successful conversion to oral diabetic therapy significantly decreases the glycosylated hemoglobin level.

Decision-analytic valuation of clinical information systems: application to an alerting system for coronary angiography

BACKGROUND

Many patients who need coronary angiography fail to get it and they have decreased survival as a result. This study demonstrates the use of decision analysis to predict the survival value of an alerting system for necessary angiography.

METHODS

Data on the use of angiography and survival after myocardial infarction (MI) were taken from a published cohort study. The expected value of information (EVI) was calculated for alerts that angiography is necessary. Maximal EVI was estimated by assuming that alert advice is always followed. Sensitivity analysis relaxed that assumption. Hypothetical data were generated to demonstrate EVI analysis for narrower subcohorts.

RESULTS

A maximally effective alerting system would increase survival in this cohort by 2.2% over 1-4 years after MI. The system would therefore need to be applied to 46 people to prevent one death. Its effectiveness would decrease linearly with decreasing adherence to its advice. Given sufficiently detailed outcome and prevalence data, EVI analysis could also predict the survival value of the system's individual data elements.

CONCLUSIONS

An alerting system that ensures necessary angiography post-MI should have a survival value comparable to the value of t-PA over streptokinase. EVI analysis provides a framework for predicting the overall effectiveness of information systems and for understanding the contribution of individual features to a system's effectiveness.

Structured entry of radiology reports using World Wide Web technology

Structured data entry--in which information is entered by using predetermined data elements and formats--has the potential to improve the radiology reporting process. The dependence on particular computer hardware and software platforms has posed a barrier to wider use of this approach. The World Wide Web (WWW), a client-server protocol for delivery of multimedia data via the Internet, was used to achieve platform-independent structured entry of radiology reports. A developmental system for structured entry of radiology reports, called SPIDER, incorporates a knowledge base of hierarchically organized concepts, a WWW server, and two specialized programs. The WebForm program transforms the system's knowledge into graphical WWW data-entry forms; the WebReport program converts data entered on these forms into outline-format reports. SPIDER received favorable evaluations from sonographers and physicians who used the system to record the results of several test cases. WWW technology can be used to achieve platform-independent entry of the results of radiologic procedures.

Alcohol and the NIDDM patient

Historically, alcohol use by the diabetic patient has been controversial. Recent studies in the general population have shown an improvement in mortality with moderate alcohol intake (one to three drinks per day). This improved mortality is greatest in those individuals who have a higher risk of ischemic heart disease. The mechanisms of the beneficial effects of alcohol include positive effects on insulin resistance, HDL cholesterol, platelet aggregation, and fibrinolysis. Since the diabetic patient has an especially high risk of ischemic heart disease because of these factors, the use of a moderate amount of alcohol should not be discouraged. The short-term risks of heavy or continuous alcohol intake include hypoglycemia, glucose intolerance, and ketone and lactate accumulation. In the long term, heavy alcohol intake is associated with an increased prevalence of cancer, hypertension, cirrhosis of the liver, and symptomatic neuropathy. Moderate alcohol intake taken with a meal has been shown to have little or no effect on postprandial glycemic excursions.