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[Doppler study of gluteal arteries. A useful tool for excluding gluteal arterial pathology snd an important adjunct to lower limb Doppler studies].

PURPOSE: 1) To determine the negative predictive value (VPN) of duplex scan in patients complaining of buttock or hip pain and thereby to distinguish vascular claudication from other musculoskeletal or neurological diseases. 2) To show its complementarity in doppler investigation of lower limb arteries. MATERIALS AND METHODS: Prospective study by duplex scan and arteriography of 60 gluteal arteries in 30 consecutive patients referred to check up for lower limb arteriopathy or sexual impotence. Duplex scan was performed by posterior approach. Correlation between doppler ultrasound and arteriography was studied. RESULTS: The study of normal arteries was possible in all cases and only one normal gluteal artery could not be detected in a diabetic overweight patient. On 60 arteries, sensitivity of duplex was 100 percent, specificity 96 percent and VPN 100 percent. Significant obstructive lesions were always associated with pathological velocimetric waveform or were not detected. CONCLUSIONS: Buttock claudication can appear like a typical vascular claudication or mimic neurological or musculoskeletal diseases. It is very useful to rule out a vascular causality responsible for buttock or hip pain by simple, non-invasive and cheap exploration. A normal doppler ultrasound of gluteal arteries can rule out vascular disease responsible for buttock or hip pain thereby avoiding arteriography. The strategy of diagnostic or therapy can be modified by such additional information as shown in two case reports.

Aged↗

Validation of scanning laser Doppler flowmetry against single point laser Doppler flowmetry in the measurement of human gastric serosal/muscularis perfusion.

BACKGROUND: Single point laser Doppler (LDF) has been employed intra-operatively to measure gastro-intestinal tissue perfusion, but despite reports that it may have a role in predicting post-operative complications consequent upon hypo-perfusion, methodological drawbacks have prevented its routine clinical application. Scanning laser Doppler flowmetry (SLDF) may address these drawbacks, but this new development has not been previously validated in human gastro-intestinal tissue. AIMS: This study assessed the ability of Scanning laser Doppler flowmetry to measure human gastric perfusion. METHODS: 10 patients undergoing oesophageal resection were studied. In each 6 measurements of gastric corporal serosal/muscularis were made over 30 seconds using the previously validated single point LDF technique. A single 1 cm2 SLDF scan was made of the same area prior to any vascular division. These measurements were repeated after partial gastric devascularisation and the two techniques' measurements then compared. RESULTS: Correlation between the 2 methods was good (coefficient of correlation was 0.955 (p<0.01). The mean bias (scan - single point PUs) was -3 PUs (95% CIs 16.3 to 45 PUs) and the limits of agreement were -64 to 58 PUs. The coefficients of variation for the 6 sets of single point measurements made in each patient ranged between 3.0% and 30.4% (mean = 12.5%). CONCLUSION: These results validate SLDF as a method of measuring gastric tissue perfusion intra-operatively.

Esophagectomy↗

Pulsed Doppler study of a case of coarctation of the aorta: demonstration of a continuous Doppler frequency shift.

Pulsed Doppler echocardiography was used to assess flow across a severe coarctation of the aorta. The high peak systolic Doppler frequency shift correlated well with the gradient measured at cardiac catheterization. A Doppler frequency shift was present throughout diastole, suggesting pan-diastolic flow across the coarctation. This finding may be a marker of severe coarctation of the aorta.

Aortic Coarctation↗

Investigation of Doppler waveforms in porcine renal allografts: Doppler-pathologic correlation.

A porcine model was devised to investigate Doppler waveforms in dysfunctional renal allografts. NIH miniature pigs served as allografts donors and recipients. Renal transplantation was effected into the recipient pelvis while the left normotopic kidney was subjected to warm ischemia in order to induce acute tubular necrosis (ATN). Doppler demonstration of allograft arterial occlusion in six animals was confirmed at surgery. Increased pulsatility of intrarenal arterial signals constituted evidence of vascular rejection in two animals. Biopsies confirmed the diagnosis in both cases. Histologic changes of ATN were identified in two native kidneys subjected to ischemia. No waveform or pulsatility alterations were observed in these animals. The porcine model provides for the investigation of allograft Doppler waveforms in a controlled setting with free access to biopsy and operative pathologic correlation.

Animals↗

Comparison of flow disturbances in small carotid atheroma using a multi-gate pulsed Doppler system and Doppler color flow imaging.

The capacity of a multi-gate pulsed Doppler (MPD) system and Doppler color flow imaging (DCFI) for the evaluation of flow patterns was studied in 14 patients with 17 nonstenotic carotid plaques (luminal narrowing less than 40%). Plaque morphology was assessed by means of a high-resolution B-mode system with subsequent three-dimensional reconstruction of the lesion surface. MPD velocity profiles obtained proximally, centrally and distally to the plaque (51 analyses) were normal in 31 sites corresponding to 28 undisturbed and 3 turbulent flow patterns assessed by Doppler color flow imaging (90% specificity). Of the 10 irregular MPD flow profiles, DCFI detected turbulence in 7 (70% sensitivity). 10 asymmetric MPD waveforms without irregularities were normal in 7 and turbulent in 3 DCFI studies. These results suggest, that MPD is superior to DCFI for the detection of nonturbulent flow asymmetry nearby small carotid plaques. However, DCFI displays turbulence with a high specificity and reasonable sensitivity and visualizes the morphologic-hemodynamic interaction in carotid atherosclerosis simultaneously.

Aged↗

Comparison of transthoracic Doppler echocardiography to intracoronary Doppler guidewire measurements for assessment of coronary flow reserve in the left anterior descending artery for detection of restenosis after coronary angioplasty.

Transthoracic Doppler echocardiography (TDE) has been described as a feasible and accurate technique to noninvasively assess coronary flow reserve (CFR) in the left anterior descending artery (LAD). This study was designed to evaluate whether serial assessment of CFR in the LAD using TDE allows detection of restenosis after previously performed angioplasty. Thirty-three consecutive patients with single-vessel coronary artery disease of the LAD scheduled for angioplasty underwent assessment of coronary flow velocity at rest and during adenosine-induced hyperemia in the distal LAD using high-frequency TDE. CFR was calculated as the ratio of hyperemic to basal systolic/diastolic mean velocity. Investigations were performed before and immediately after angioplasty, and at the time of control angiography after 3 months. CFR results by TDE were compared with intracoronary Doppler guide wire measurements. Adequate pulse-wave Doppler signals to measure CFR were obtained in 30 patients (91%) using TDE. There was close correlation between echocardiographically and intracoronary derived CFR results (r = 0.80, 0.79, and 0.87 before angioplasty, early after, and at 3- month control angiography, respectively; p <0.001). Using a cut-off value of CFR < or =2.0 to identify significant coronary artery disease, TDE detected LAD restenosis with a sensitivity of 89% and specificity of 90%. Thus, high-frequency TDE is a feasible technique to noninvasively assess CFR in the LAD with results closely corresponding to invasive measurements. Defining a cut-off value of CFR < or =2.0, the technique has the potential to reliably detect LAD stenosis after coronary intervention.

Adenosine↗

Endoscopic ultrasound Doppler probes for velocity measurements in vessels in the upper gastrointestinal tract using a multifrequency pulsed Doppler meter.

To quantify flow velocity in vascular structures in the upper gastrointestinal tract, prototype ultrasound Doppler transducers having frequencies of 5 and 10 MHz were designed. Connected to an advanced pulse ultrasound Doppler meter via an isolation transformer for patient safety, these transducers enabled the recording of flow velocity in vessels within an surrounding the wall of the GI tract. This set up improves the endoscopic ultrasound Doppler method by extending the measurable depth-range by using two frequencies, permitting independent selection of measuring depth and sample volume length, and giving an output format which includes full spectral analysis, simultaneous ECG and capabilities of displaying two additional signals.

Blood Flow Velocity↗

Intracranial blood flow: quantification with duplex Doppler and color Doppler flow US.

The authors compared changes in cerebral blood flow (CBF), determined by means of injection of radiolabeled microspheres, with Doppler blood flow measurements obtained simultaneously in the middle (n = 9) and anterior cerebral arteries (n = 3) in 12 newborn lambs. Doppler estimates of blood flow and mean blood flow velocity correlated well with changes in CBF. However, with changes in mean blood flow velocity, the degree of change in CBF tended to be underestimated. The resistive index correlated well with perfusion pressure but correlated weakly with cerebrovascular resistance and poorly with changes in CBF. Doppler blood flow estimates and mean blood flow velocities correlate well with changes in CBF and allow significant improvement in accuracy over instantaneous velocity or pulsatility measurements alone. Determination of absolute blood flow remains difficult due to systolic and diastolic differences in vessel diameter and intrinsic error in true diameter measurement with currently available color flow technology.

Animals↗

Noninavasive angiography for the diagnosis of carotid artery disease using Doppler ultrasound (carotid artery Doppler).

To detect stenosis in the carotid artery with a bidirectional continuous-wave Doppler ultrasound device, the following noninvasive procedure, applied on 800 patients and compared with 249 angiograms of 186 patients, has proved to be about 90% reliable. Measurements of flow signals were taken over the terminal branches of the ophthalmic artery (supratrochlear and supraorbital arteries) and averaged. Compression of superficial temporal and facial arteries revealed flow direction and common carotid artery compression revealed the supplying blood vessel and the effectiveness of the circle of Willis. Measurements over the common carotid arteries were used to evaluate peripheral resistance. A set of eight criteria was used; the diagnostic value of each criterion was calculated by comparing 138 pathological Doppler findings in 123 patients with the angiograms. If reverse flow direction in supratrochlear or supraorbital artery was used alone, only 43% correct diagnoses would have resulted. A more severe stenosis is not necessarily correlated with a more weighted criterion; a subset of criteria is less efficient than the combination of all criteria. Application during 32 extracranial endarterectomies on 28 patients informed the surgeon immediately about the hemodynamic effect of the surgical intervention. Rethrombosis was diagnosed in two patients by postoperative Doppler examination.

Carotid Artery Diseases↗

Evaluation of arteriovenous fistulas and pseudoaneurysms in renal allografts following percutaneous needle biopsy. Color-coded Doppler sonography versus duplex Doppler sonography.

One hundred one patients with renal allografts were studied by two independent observers using duplex Doppler sonography (DDS) and color-coded Doppler sonography (CCDS). In all patients, single or multiple percutaneous needle biopsies of the transplant had been performed 1 to 30 days before. In 6 patients CCDS following the biopsy demonstrated an area of combined red and blue color-coded blood flow within the renal parenchyma (n = 5) or within the sinus (n = 1); the Doppler waveform was abnormal in these areas with signals above and below the zero line indicating turbulent blood flow. Consecutive intraarterial digital subtraction angiography (DSA) revealed the presence of an arteriovenous fistula (n = 4) or of a pseudoaneurysm (n = 2). In one patient, gross hematuria with obstruction of the bladder occurred as a complication of a pseudoaneurysm within the renal sinus; the bleeding could not be stopped by embolization of the lesion and the kidney had to be removed. DDS demonstrated the lesion in only one of the six patients. Thus, CCDS is the method of choice for noninvasive detection of vascular lesions due to percutaneous biopsy.

Adolescent↗

Conventional spectral Doppler and color Doppler ultrasound imaging. Principles, limitations, artifacts and clinical indications in hepatology.

The physical principles, limitations, errors and indications of conventional Doppler and color encoded Doppler sonography are reviewed and their applications in the investigation of liver, spleen, portal and suprahepatic portal venous circulation are analysed. The actual possibilities and advantages of Doppler imaging, both in normal conditions and in pathologic ones, such as portal hypertension, portal venous thrombosis or cavernous transformation, liver cirrhosis, hepatoma and liver transplantation are discussed.

Artifacts↗

Duplex Doppler evaluation of renal allograft dysfunction: Doppler signal quantitation and pathologic correlation.

The value of quantitative duplex Doppler sonography in discriminating the different possible causes of renal transplant dysfunction was prospectively studied in 60 patients during 65 episodes of renal function impairment. Final diagnosis at histology was acute rejection (n: 30), acute tubular necrosis (n: 4), cyclosporin nephrotoxicity (n: 16) and chronic rejection (n: 15). Duplex sonography was done the day a percutaneous biopsy was taken and before any therapy was started. Arterial Doppler signals obtained from the segmental, interlobar and arcuate arteries were both morphologically and quantitatively analysed. For quantitative analysis we used the resistive index as proposed by Pourcelot on the one hand, and introduced a variant resistive index on the other hand. Morphological analysis yielded no discriminative value. Comparing both quantitative methods--the resistive index of Pourcelot and the variant resistive index--clearly higher specificities--71% using the variant resistive index, 28% using the resistive index of Pourcelot--for excluding acute rejection from the other possible causes of renal function impairment could be achieved. A nephrectomy was done on 7 patients with severe transplant dysfunction. Microangiographies performed on these nephrectomy specimens were correlated with previous Doppler studies and with histology.

Graft Rejection↗

Improved diagnosis of vascular dissection by ultrasound B-flow: a comparison with color-coded Doppler and power Doppler sonography.

The purpose was to evaluate the diagnostic results of different ultrasound techniques: color-coded Doppler (CCD), power Doppler (PD) and B-flow in the diagnosis of vascular dissection. Findings from 68 patients with arterial dissection proven either by vascular ultrasound (US) or by magnetic resonance angiography (MRA), computed tomographic angiography (CTA) or intra-arterial digital subtraction angiography (DSA) were reviewed in retrospect. The study compared results from three different modes of ultrasound, i.e., CCD, PD and B-flow, in dissections of the carotid artery (n=11), of the vertebral artery (n=9), of the abdominal aorta (n=13), of the iliac artery (n=12) and of the femoral artery (n=23). MRA, CTA and DSA were considered as reference standard. The sensitivity of CCD for detecting all dissections was 78%, 84% for the PD and 98% for B-flow. For carotid artery dissection, the sensitivity of CCD, PD and B-flow was 82, 91 and 98%, for the vertebral artery 67, 78 and 98%, for the abdominal aorta 85, 85 and 98%, for the iliac artery 67, 75 and 98%, for the femoral artery 83, 87 and 98%, respectively. Intima flaps, fissures of membranes and residual flow within the true and false lumen were better detected by B-flow than by CCD and PD. The lack of angle dependence of the US probe in B-flow made the examination procedure easier. In the cine mode of B-flow, the pulse synchronic movement of the membrane was more apparent than in any other imaging method. With B-flow, accuracy for the diagnosis of arterial dissection is improved compared to CCD and PD. Flow within the true and false lumen, low-echo thrombi, intramural hematoma and even movements of the dissection membrane are clearly distinguished.

Adult↗

Color Doppler, power Doppler and B-flow ultrasound in the assessment of ICA stenosis: Comparison with 64-MD-CT angiography.

The purpose of this study is to investigate the diagnostic potential of color-coded Doppler sonography (CCDS), power-Doppler (PD) and B-flow ultrasound in assessing the degree of extracranial internal carotid artery (ICA) stenosis in comparison to CT-angiography (MD-CTA). Thirty-two consecutive patients referred for CTA with 41 ICA-stenoses were included in this prospective study. MD-CTA was performed using a 64 row scanner with a CTDIvol of 13.1 mGy/cm. In CTA, CCDS, PD and B-flow, the degree of stenosis was evaluated by the minimal intrastenotic diameter in comparison to the poststenotic diameter. Two radiologists performed a quantitative evaluation of the stenoses in consensus blinded to the results of ultrasound. These were correlated to CTA, CCDS, PD and B-flow, intraoperative findings and clinical follow-up. Grading of the stenoses in B-flow ultrasound outperformed the other techniques in terms of accuracy with a correlation coefficient to CTA of 0.88, while PD and CCDS measurements yield coefficients of 0.74 and 0.70. Bland-Altman analysis additionally shows a very little bias of the three US methods between 0.5 and 3.2 %. There is excellent correlation (coefficient 0.88, CI 0.77-0.93) with 64-MD-CTA and B-flow ultrasound in terms of accuracy for intrastenotic and poststenotic diameter. Duplex sonography is useful for screening purposes.

Aged↗

Power Doppler: an advance over colour Doppler for transcranial imaging?

The aim of this study is to compare the ability of mean frequency-based colour Doppler (CD) and power Doppler (PD) to identify the basal cerebral arteries in normal subjects. Fifty volunteers were recruited into the study. The temporal acoustic window was used to image the basal cerebral arteries bilaterally. The number of positively identified vessels was recorded, first using CD and then with PD. Our results show that both modalities were equally effective at demonstrating the anterior cerebral artery (ACA), the middle cerebral artery mainstream (MCA M1) and the precommunicating segment of the posterior cerebral artery (PCA P1; ACA: 82% and 83%; MCA M1: 84% and 89%; PCA P1: 81% and 83%; CD and PD, respectively). However, the M2 portion of the MCA (CD: 25%, PD: 54%; difference 29% [95% CI 20-38%]), the P2 portion of the PCA (CD: 67%, PD: 75%; difference 8% [95% CI 3-13%]) and the posterior communicating artery (CD: 15%, PD 32%; difference 17% [95% CI 10-24%]) were all identified in a significantly greater proportion of subjects using PD. Although its clinical value remains undetermined, PD offers significant advantages over colour-coded sonography in imaging small-calibre and low-flow arteries and those which run at unfavourable angles to the ultrasound beam.

Adolescent↗

Disagreement between tissue Doppler imaging and conventional pulsed wave Doppler in the measurement of myocardial performance index.

AIM: Myocardial performance index (MPI) is usually measured with pulsed wave Doppler (PWD). Our aim was to assess the degree of agreement between PWD and a method based on tissue Doppler imaging (TDI). METHODS AND RESULTS: Seventy-five patients with prior myocardial infarction and 20 healthy subjects underwent measurement of time intervals and MPI with PWD and pulsed TDI at septal and lateral sides of mitral annulus. MPI and TDI-MPI at septal side showed the best intraclass correlation coefficient (ICC=0.54; p<0.0005). Ninety-five percent interval of agreement ranged from -0.27 to 0.22. These differences were attributed to discrepancies in isovolumic contraction and relaxation times. In the healthy group the results were similar (ICC=0.44), although the 95% interval of agreement was lower (from -0.13 to 0.12). CONCLUSIONS: The agreement between PWD and TDI in the measurement of MPI is only moderate. This should be taken into account in the interpretation of studies in which TDI is used for this measurement.

Aged↗

Combination of pulsed-wave Doppler and real-time three-dimensional color Doppler echocardiography for quantifying the stroke volume in the left ventricular outflow tract.

Real-time three-dimensional (3-D) color Doppler echocardiography (RT3D) is capable of quantifying flow. However, low temporal resolution limits its application to stroke volume (SV) measurements. The aim of the present study was, therefore, to develop a reliable method to quantify SV. In animal experiments, cross-sectional images of the LV outflow tract were selected from the RT3D data to calculate peak flow rates (Q(p3D)). Conventional pulsed-wave (PW) Doppler was performed to measure the velocity-time integral (VTI) and the peak velocity (V(p)). By assuming that the flow is proportional to the velocity temporal waveform, SV was calculated as alpha x Q(p3D) x VTI/V(p), where alpha is a temporal correction factor. There was an excellent correlation between the reference flow meter and RT3D SV (mean difference = -1. 3 mL, y = 1. 05 x -2. 5, r = 0. 94, p < 0. 01). The new method allowed accurate SV estimations without any geometric assumptions of the spatial velocity distributions.

Animals↗

Assessment of mitral annular dynamics during diastole by Doppler tissue imaging: comparison with mitral Doppler inflow in subjects without heart disease and in patients with left ventricular hypertrophy.

The purpose of this study was to determine the normal pattern and magnitude of mitral annular velocities in diastole by Doppler tissue imaging (DTI) and to assess whether this is altered in patients with left ventricular hypertrophy. Mitral annulus velocities were measured by DTI. Peak and time-velocity integral were measured from the DTI tracings and the timing of the velocities in relation to electrocardiogram. DTI was compared with M-mode echo of the annulus and mitral inflow Doppler velocities. Integrated annular velocities by DTI correlated with the annular displacement. Early diastolic velocities decreased with age and in patients with left ventricular hypertrophy. In the hypertrophy group, early diastolic velocities were significantly lower than normal even after correcting for age. Patients with left ventricular hypertrophy also showed a delay in peak early diastolic mitral annular velocity (5.5 +/- 21 msec after the E wave). In conclusion, mitral annular velocity in diastole is readily recorded by DTI. The magnitude and the pattern of these velocities are significantly altered by age and by left ventricular hypertrophy. This method provides a new insight into diastolic filling events and may prove useful in detecting abnormal diastolic function.

Adult↗