OBJECTIVE: The purpose of this study was to construct a method of vessel edge detection that correctly identifies vessel pixels and to compare the interuser variability of cine phase contrast MR volumetric flow rates obtained with the conventional manual method and an automated method. MATERIALS AND METHODS: The automated method was developed based on a magnitude image threshold value and compared with the manual method in a flow phantom (three users) and in velocity images of the portal vein (five users). The threshold value determined from the magnitude image was applied to a region of interest surrounding the vessel of interest on the magnitude image to construct a vessel edge detection mask m(x,y). The velocity images were then multiplied by the mask m(x,y) and volumetric flow rates determined using the identified vessel pixels. RESULTS: In the flow phantom, flow measurements with the magnitude threshold method had significantly less interuser variability compared with the manual method (p < 0.01) and were within 10% (mean 6.0%) of the actual flow versus 35% (mean 18.6%) with the manual method. Regarding flow measurements in the portal vein of six volunteers, the magnitude threshold method was significantly more precise (p < 0.01) than the manual method with a mean standard deviation between the five users of 40.4 +/- 12.9 ml/min (range 22-60 ml/min) and 110.4 +/- 32.7 ml/min (range 70-155 ml/min), respectively. CONCLUSION: The magnitude threshold method of vessel edge detection developed in this study yields flow measurements that are accurate in the model system and have significantly less interuser variability than the manual method. This method shows promise for improving the precision of cine phase contrast flow measurements.

Adult↗

PubMedDate not supplied

The relationship of life stressors and maternal depression to pediatric asthma morbidity in a subspecialty practice.

OBJECTIVE: To examine the relationships among demographic characteristics, caregiver life stressors, and depressive symptoms of mothers and their children's asthma morbidity. SETTING: Three pediatric asthma subspecialty programs, 2 in the inner city and 1 in the suburbs. DESIGN: Cross-sectional census sample of caregivers of children with asthma: interviews mostly with mothers (N = 123) regarding their children's asthma symptoms and health care utilization. Information collected on demographics and caregivers' own recent life stressors and depressive symptoms. SUBJECTS: Caregivers of children ages 18 months to 12 years with asthma at their subspecialty visit. MEASURES: Structured interviews: a survey instrument prepared for this study and standardized instruments for depression (Center for Epidemiologic Studies--Depression) and life stressors (Crisis in Family Systems). RESULTS: A total of 32% of respondents' children had high asthma morbidity, 28% intermediate, and 40% low. Caregiver life stressors and depression and the children's sex showed the strongest relationships to asthma morbidity in a model that also included race, residence, and Medicaid status. Children were more likely to have high morbidity if they had caregivers with more depressive symptoms and negative life stressors and if they were female. CONCLUSIONS: Respondents experienced many life stressors and symptoms of depression while managing their children's illness. Caregivers' lives may affect their children's asthma morbidity, offering empirical evidence for the potential value of targeted case management for children in subspecialty care.

Analysis of Variance↗

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Intraarterial signal on fluid-attenuated inversion recovery images: a measure of hemodynamic stress?

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Brain↗

PubMedDate not supplied

Primary intracranial CNS lymphoma: MR manifestations.

We reviewed MR scans of 10 patients with biopsy-proved primary CNS lymphoma. Twenty-five lesions were identified in 10 patients (four with AIDS and six without AIDS). In general, the typical lesion of CNS lymphoma was found to have the following MR characteristics: they were slightly hypointense on T1-weighted images and slightly hyperintense on proton density and T2-weighted images relative to gray matter; they induced mild edema and mild to moderate mass effect. In AIDS patients, 82% of the lesions were smaller than 2 cm in diameter, and were frequently located in the temporal lobes and basal ganglia; they were often multiple. In non-AIDS patients, 75% of the lesions were larger than 2 cm in diameter and were primarily found in the deep parietal lobe; most were solitary.

Acquired Immunodeficiency Syndrome↗

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