Valvular function of peripheral veins after hyperemic dilation

Andersson, Jonas; Thurin, Anders; Thulesius, Olav

doi:10.1016/s0741-5214(96)80040-1

Cited by 15 publications

(9 citation statements)

References 4 publications

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“…So far, in vivo MRI investigations of the human distal extremities have been limited to morphologic imaging of skin layers, joints, and vessel anatomy (9 -12), not including functional parameters. Commonly, blood flow velocities in the human distal extremities are obtained by ultrasound (US) investigations (13,14). US flow measurements have the advantage of being fast and flexible; on the other hand, they do not provide detailed anatomic information.…”

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confidence: 99%

High‐resolution blood flow velocity measurements in the human finger

Klarhöfer

Csapó

Bálassy

et al. 2001

Magnetic Resonance in Med

138

109

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MR phase contrast blood flow velocity measurements in the human index finger were performed with triggered, nontriggered, and cine acquisition schemes. A strong (G max ‫؍‬ 200 mT/m), small bore (inner diameter 12 cm) gradient system inserted in a whole body 3 Tesla MR scanner allowed highresolution imaging at short echo times, which decreases partial volume effects and flow artifacts. Arterial blood flow velocities ranging from 4.9 -19 cm/sec were measured, while venous blood flow was significantly slower at 1.5-7.1 cm/sec. Taking into account the corresponding vessel diameters ranging from 800 m to 1.8 mm, blood flow rates of 3.0 -26 ml/min in arteries and 1. Phase contrast (PC) MRI to quantify blood flow velocities has been validated in several studies (1-3). Most human applications focus on large vessels such as the aorta, carotids, or femoral arteries. This is due to the fact that systematic errors strongly increase with decreasing number of image pixels that cover the vessel lumen under investigation (4,5). Models that correct for partial volume effects have been developed which allow the acquisition of flow velocity values from vessels covered by only a few pixels (6 -8). In this study, a different approach was performed to overcome problems associated with partial volume effects. We used a strong gradient system that allows high-resolution phase contrast MRI of the human finger. In our experiments, the main vessels of the human index finger were covered by at least 16 pixels, which is sufficient to keep systematic errors due to partial volume effects small (4). So far, in vivo MRI investigations of the human distal extremities have been limited to morphologic imaging of skin layers, joints, and vessel anatomy (9 -12), not including functional parameters. Commonly, blood flow velocities in the human distal extremities are obtained by ultrasound (US) investigations (13,14). US flow measurements have the advantage of being fast and flexible; on the other hand, they do not provide detailed anatomic information. The information about the patency of large vessels is a cardinal aspect in the assessment of general arteriosclerosis in tissues (15). However, little is known about the role of smaller arteries. Although their general functionality can be tested by a number of simple physical tests (e.g., exercise), these tests still provide us with no visual information on vessel size or orientation. For planning distal reconstructive surgery in cases of severe arteriosclerosis, a vital role could be played by the combination of functional information (e.g., blood flow velocity) and complementary 3D images of individual vessels. Such information could also be helpful in staging general and/or microangiopathy of distal body parts. To our knowledge, we performed the first MR blood flow velocity measurements in human peripheral vessels with diameters as low as 800 m without the need to correct for partial volume effects. MATERIALS AND METHODSBlood flow velocities were measured in the index fingers of five healthy male s...

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mentioning

confidence: 99%

High‐resolution blood flow velocity measurements in the human finger

Klarhöfer

Csapó

Bálassy

et al. 2001

Magnetic Resonance in Med

138

109

View full text Add to dashboard Cite

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“…However, quantification of venous reflux is an important aspect of venous disease research with particular relevance in comparing new techniques of treatment such as a valve repair, graft or external cuffs, and for the evaluation of stockings and other medications. Several techniques have been available for quantitative evaluation of chronic venous insufficiency (CVI), including duplex ultrasound (DUS), [1][2][3][4][5][6] strain-gauge plethysmography, and air plethysmography (APG). [7][8][9][10] DUS and APG are the two noninvasive techniques most widely used for the evaluation of patients with CVI.…”

Section: Introductionmentioning

confidence: 99%

Quantitative Assessment of Chronic Venous Insufficiency Using Duplex Ultrasound and Air Plethysmography

Asbeutah

Riha

Cameron

et al. 2006

Journal for Vascular Ultrasound

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Purpose Using noninvasive methods, we studied patients 5 years after they received an index deep vein thrombosis (DVT) to quantify venous reflux in the lower limb and to relate it to venous disease severity. Methods Thirty-eight patients (76 limbs) with DVT were studied 5 years after being diagnosed by ultrasound and/or venography and treated with warfarin through a hospital-in-the-home program. There were 15 men and 23 women, their average age (±SD) was 56.7 years (±16 years), and their average body mass index (±SD) was 28.8 (±5.7 kg/m2). The limbs were classified according to the clinical, etiologic, anatomic, and pathophysiologic (CEAP) clinical classification. There were 10 limbs in CEAP class 0, 28 in classes 1–3, and 22 in classes 4–6. Duplex ultrasound and air plethysmography (APG) techniques were used to assess venous reflux. A total of 14 limbs of healthy volunteers underwent APG of the lower limb for comparison. Results At follow-up, 60 limbs exhibited reflux, 35 in the DVT affected limb and 25 in the non-DVT limb. DUS indexes did not differentiate between venous disease severity in terms of reflux duration or reflux flow volume. APG indexes were significantly different, with venous filling index (VFI) being most discriminating. In limbs with skin changes, median (range) VFI was 3.5 mL/sec (1.6–17), compared with 1.5 ml/sec (0.6–3.4) in limbs with class 0, 2.1 ml/sec (0.6–11) in limbs with classes 1–3, and 0.8 ml/sec (0.6–1.7) in normal controls. Conclusion Duplex ultrasound provides excellent anatomical imaging, but its indexes lack discrimination in relation to disease severity. However, APG indexes do differ in relation to clinical venous disease severity, and VFI appear to be a useful index for following the progression of chronic venous insufficiency disease.

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“…In addition, there is not a good correlation between VCT and clinical severity of venous disease [7,12,22]. The reflux/augmentation ratio, or reflux volume index (RVI), has been shown to be reliable in experimental [3] and clinical settings [2,[10][11]20]. The RVI has also been found to correlate well with clinical outcome in patients after venous valvuloplasty [18][19].…”

Section: Introductionmentioning

confidence: 99%