The Doppler signal: where does it come from and what does it mean?

Nelson, Thomas R.; Pretorius, Dolores H.

doi:10.2214/ajr.151.3.439

Cited by 210 publications

(144 citation statements)

References 15 publications

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“…The indices depend on ratios involving the peak systolic velocity (PSV), the end diastolic velocity (EDV) and mean velocity (MV) through one cycle. RI is one of the primary indices used clinically and is calculated through the following equation (6).…”

Section: Methodsmentioning

confidence: 99%

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia

et al. 2012

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Objective: The aim of this work is to study the resistive index (RI) of prostatic blood fl ow by transrectal power Doppler sonography in benign prostatic hyperplasia (BPH) to determine its correlation with other parameters of BPH. Materials and Methods: Eighty-two male patients aged 52-86 years with lower urinary tract symptoms (LUTS) due to BPH were included in the study. Patients with prostate cancer, neurogenic bladder, or with other pathology (e.g. prostatitis, bladder stone) were excluded from the study. All patients were evaluated by full history including Internatinoal Prostate Symptoms Score (IPSS), general and local examination (DRE), neurologic examination, urofl owmetry, laboratory investigations including urine analysis, routine laboratory tests and serum prostate specifi c antigen (PSA). Transrectal ultrasonography was used to calculate the total prostatic volume. Transrectal Power Doppler Ultrasound (PUD) was used to identify the capsular and urethral arteries of the prostate and to measures the RI value. Results: The mean prostate volume was 75.1 ± 44.7 g. The mean RI of the right and left capsular arteries were 0.76 ± 0.06 and 0.76 ± 0.07, respectively. The mean RI of the urethral arteries was 0.76 ± 0.08. There was a high signifi cative correlation between the increase of the RI of the right and left capsular and urethral arteries and the degree of obstruction (P value < 0.001), severity of symptoms (P value < 0.001) and also the prostatic volume (P value < 0.001). Conclusion: Resistive index of the prostatic blood fl ow can be applied as an easy and non-invasive tool to evaluate the lower urinary tract obstruction due to BPH. Evaluation of the resistive index of prostatic blood fl ow in benign prostatic hyperplasia _______________________________________________

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Section: Methodsmentioning

confidence: 99%

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia

et al. 2012

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“…The blood flow velocity (v) is directly proportional to the frequency shift (Df) and can be calculated by the standard Doppler equation [26,28,29]: Fig. 1.…”

Section: Transesophageal Doppler Sonographymentioning

confidence: 99%

“…where c is the velocity of the ultrasound waves in body tissue (average 1,540 m s -1 in soft tissue [28]) and f T the emitted frequency. The cosine of the angle between Doppler beam and blood flow (cos h) is a correction factor needed to adjust for the angle of insonation.…”

Section: Transesophageal Doppler Sonographymentioning

confidence: 99%

Transesophageal Doppler devices: A technical review

Schober

Loer

Schwarte

2009

J Clin Monit Comput

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“…In 2D-cine-PC MRI, pulsatility or resistive index was used to assess flow profiles at the popliteal artery (22). A resistive index, which associates with arterial resistance to blood flow, has been defined as (A Ϫ B)/A, where A is the systolic peak velocity and B is the end-diastolic velocity (23). Therefore, resistive index was calculated from the originally obtained 16 velocity images.…”

Section: Magnetic Resonance Studiesmentioning

confidence: 99%

Low Blood Flow Estimates in Lower-Leg Arteries Predict Cardiovascular Events in Japanese Patients With Type 2 Diabetes With Normal Ankle-Brachial Indexes

et al. 2006

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OBJECTIVE -To examine the association of baseline measures in lower-leg arteries and conventional cardiovascular risk factors with the incidence of cardiovascular disease (CVD) events in type 2 diabetic patients with normal ankle-brachial indexes (ABIs) (Ͼ0.9).RESEARCH DESIGN AND METHODS -We studied 129 type 2 diabetic patients and 35 age-matched nondiabetic subjects with no apparent CVD consecutively admitted to our hospital. At baseline, total flow volume and resistive index, as an index of vascular resistance, at the popliteal artery was evaluated using gated two-dimensional cine-mode phase-contrast magnetic resonance imaging. Patients were followed 4.8 Ϯ 1.5 years (range 3.0 -8.2) or until their first event of CVD.RESULTS -On follow-up, 16 patients developed primary CVD events. Patients with CVD had lower blood flow (P Ͻ 0.01) and higher vascular resistance (P Ͻ 0.05) than patients without CVD. When the patients were grouped into tertiles according to their levels of total flow volume (129.6 -85.5, 85.3-63.3, and 62.7-23.8 ml/min), Kaplan-Meier analysis showed a higher probability of developing CVD events in patients in the lowest than in patients in the highest (P ϭ 0.0199, log-rank test) tertile. Multivariate Cox proportional hazards analysis revealed that the lowest tertile for flow volume (hazard ratio [HR] 8.60, 95% CI 1.61-45.97, P ϭ 0.012), hypertension (3.99, 1.12-14.25, P ϭ 0.033), and smoking status (12.01, 1.21-119.28, P ϭ 0.034) were significant independent predictors of CVD events.CONCLUSIONS -We have demonstrated that low blood flow estimates in lower-leg arteries may be predictive for CVD events among Japanese patients with type 2 diabetes even though they have a normal ABI. Diabetes Care 29:1884 -1890, 2006D iabetic patients are likely to develop cardiovascular disease (CVD), including stroke, myocardial infarction, and peripheral artery occlusive disease (PAOD) (1). These manifestations of atherosclerosis frequently coexist in the same individual (2). Therefore, to identify these patients before the onset of CVD, ankle-brachial index (ABI) is generally used as a predictive marker of CVD (3).Furthermore, diabetic patients with chronic hyperglycemia are known to have stiffer arteries (4). Arterial stiffness leads to increased systolic pressure and ventricular mass and hampers coronary filling during diastole; therefore, increased arterial stiffness may play a role in the development of CVD (5). Changes of vessel wall properties, such as nonenzymatic glycosylation of matrix proteins (6), increased intima-media thickness (7,8), and radiographically detectable medial arterial calcification (9,10) may be involved in the pathogenesis of vascular rigidity.When the atherosclerotic plaques are at an advanced stage, calcified deposits in the coronary arteries are found more frequently and in greater amounts (11). Although the detection of coronary calcium deposits by electron-beam computed tomography does not indicate the location or severity of atherosclerotic lesions, this imaging procedure can predi...

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The Doppler signal: where does it come from and what does it mean?

Cited by 210 publications

References 15 publications

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia

Evaluation of the resistive index of prostatic blood flow in benign prostatic hyperplasia

Transesophageal Doppler devices: A technical review

Low Blood Flow Estimates in Lower-Leg Arteries Predict Cardiovascular Events in Japanese Patients With Type 2 Diabetes With Normal Ankle-Brachial Indexes

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