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[Abdominal Doppler echography. Pathologic arterial signals]
L E Derchi1, C Martinoli, E Silvestri
1Istituto di Radiologia, Università di Genova.
Insights
Doppler ultrasound reveals distinct pathological flow signals in abdominal vessels linked to specific lesions. Understanding these patterns aids in diagnosing vascular diseases and hemodynamic changes.
Area of Science:
- Vascular Ultrasound
- Hemodynamics
- Medical Imaging
Background:
- Doppler examinations are crucial for assessing abdominal vessel pathologies.
- Pathological flow signals provide insights into underlying arterial hemodynamics.
- Correlation between flow patterns and specific lesions is key for diagnosis.
Purpose of the Study:
- To report and categorize major pathological flow signals in abdominal vessels.
- To correlate these signals with causative pathological lesions.
- To elucidate changes in arterial hemodynamics associated with these signals.
Main Methods:
- Analysis of Doppler ultrasound examinations of abdominal vessels.
- Categorization of pathological flow signals based on lesion location.
- Correlation of flow patterns with vessel wall lesions, peripheral resistance changes, and cardiac factors.
Main Results:
- Flow signals are grouped by lesion site: vessel walls (stenosis, aneurysms), peripheral resistance changes (increased impedance, decreased resistance in fistulas/tumors), and cardiac factors (heart rhythm, valvular disease).
- Specific patterns include widened spectrum, increased velocity, reduced velocity, vorticous flow, "to and fro" patterns, and low/slow flow.
- These patterns are directly linked to conditions like stenosis, aneurysms, arteriovenous fistulas, tumors, and post-stenotic/post-occlusive states.
Conclusions:
- Pathological Doppler flow signals in abdominal vessels are classifiable into distinct patterns.
- These patterns are reliable indicators of specific vascular lesions and hemodynamic alterations.
- Doppler ultrasound is an effective tool for diagnosing a range of abdominal vascular pathologies.
Abstract:
In this paper, the features are reported of the major pathological flow signals obtained during Doppler examinations of abdominal vessels. The patterns are correlated with the pathological lesions which may cause them, as well as with the underlying changes in arterial hemodynamics. Pathological flow signals are divided into three groups, according to the sites where the lesions producing them are located. a) Lesions of the vessel walls. In this group, both widening of spectrum due to disturbed flow and increased blood velocity from vessel stenosis are presented. Also flow alterations occurring in aneurysms (reduction of flow velocity and presence of vorticous flow) are discussed. b) Changes in peripheral resistances. Peripheral resistances may either increase or decrease due to a variety of diseases. Parenchymal edema, compression, infiltration, as well as small vessel disease, may increase vascular impedance. Fall of vascular resistances may be observed in inflammation or in arteriovenous fistulas either large (congenital or hemodialysis fistulas) or microscopic, as in many hypervascular tumors. A typical "to and fro" flow pattern was seen in vessels where flow resistance is overcome only during systole, such as in arterial pseudoaneurysms. c) Changes in rhythm or strength of the heartbeat, cardiac valvular diseases, postocclusive flow. A variety of pathological findings may be observed in these conditions. Peculiar changes in the waveforms are seen with variations in heart frequency. Changes may be detected also in aortic valvular diseases, with retrograde flow observed in patients with aortic insufficiency. Low and slow flow are seen in post-stenotic and/or postocclusive vessels.