Mean Number Of Signals Research Articles

What Do Anticoagulants Say about Microemboli?

In this study, we evaluated the microembolic signals (MES) frequency with transcranial Doppler ultrasound (TCD) in patients with atrial fibrillation (AF) under anticoagulant therapy, and we compared the treatment groups. Ninety-nine patients with nonvalvular AF with a history of stroke using warfarin (46%), 67 patients using rivaroxaban (31%), and 49 patients using dabigatran (23%), that is, a total of 215 patients, who have been referred to the stroke outpatient section of our department from May 2013 to November 2014, were included in the study. CHA(2)DS(2)VASc scoring was made for all patients, and International Normalized Ratio (INR) value was evaluated in patients using warfarin. All patients were monitored with TCD on the middle cerebral arteries bilaterally for 30 minutes. Embolic signals were evaluated according to their density and the mean number of signals in 2 consecutive recordings. The incidence of emboli in the treatment group was 32 (32%) for warfarin, 24 (36%) for rivaroxaban, and 17 (35%) for dabigatran. The analysis of variance revealed that there was no statistically significant differences between the treatment groups in terms of patients' age (P = .145), CHA(2)DS(2)VASc scores (P = .968), and the number of emboli (P = .783). As CHA(2)DS(2)VASc score increases, number of emboli increase. A statistically significant negative correlation between the number of emboli and INR scores was found in the warfarin group. The number of emboli decreases as INR decreases. As we aim to reduce the risk of emboli to a minimum with anticoagulant therapy, this screening for MES can give us an idea for the risk of stroke.

Hepatic hemangioma: quantitative color power US angiography--facts and fallacies.

To explore the origin of signals detected with color power ultrasound (US) angiography (CPA) and evaluate a semiquantitative method to assess signals in hepatic hemangiomas. Twenty-four adult patients with 27 hepatic hemangiomas (< 2 cm in diameter) and five patients with five hyperechoic hepatic metastases underwent CPA and conventional color Doppler US in this prospective study. A sponge phantom was studied to determine whether the origin of CPA signals was related to architecture. The mean number of signals and the signal density in each lesion were scored. A "diffuse blush" was seen in all capillary hemangiomas at CPA, whereas no signal was seen at color Doppler US. The sponge phantom test produced a CPA appearance similar to that of capillary hemangiomas. Quantitative analysis of CPA images of hepatic hemangiomas showed a mean of 16.1 signals per cubic centimeter and a mean signal area of 25%. Hyperechoic avascular hepatic metastases resulted in CPA images similar to those of hepatic hemangiomas, with no quantitative difference in signal count, despite a mild qualitative difference at CPA. CPA signals in hepatic hemangiomas appear to be related more to architecture than to true capillary flow. There is a qualitative difference in the strength of the blush at CPA between hepatic hemangiomas and metastases, which may be the only possible differentiating factor.