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Biomedical subjects

D S Sumner

Publications and source records attributed to D S Sumner.

At least 37 records · Page 2Linked to original sources
PubMed1995

The natural history of moderate (50% to 79%) internal carotid artery stenosis in symptomatic, nonhemispheric, and asymptomatic patients.

PURPOSE: This study was undertaken to determine the incidence of disease progression of moderate (50% to 79%) internal carotid artery stenosis in patients with symptoms, patients with nonhemispheric symptoms, and symptom-free patients and to define the risk of development of new neurologic events in each group. METHODS: Over a 6-year period, 272 patients with moderate internal carotid artery stenoses were monitored for a mean of 44 months with color-flow duplex scanning (CFS). At the time of the initial scan, 142 patients were symptom free, 87 had experienced transient ischemic attacks, amaurosis fugax, or mild strokes, and 43 had ill-defined nonhemispheric symptoms. The average number of follow-up scans was 2.4 per patient (range 1 to 11). RESULTS: During follow-up, 23 (26%) of the patients with symptoms, 17 (40%) of the patients with nonhemispheric symptoms, and 30 (21%) of the symptom-free patients had development of additional neurologic symptoms. Life-table comparison of ipsilateral ischemic events showed a significantly (p = 0.03) higher cumulative rate in the symptomatic group (20%) than in the asymptomatic group (7%) at 2 years. Mean annual stroke rates were 6% and 2% in patients in the symptomatic and asymptomatic groups, respectively. None of the patients in the nonhemispheric group had a stroke within 4 years of the initial study. Disease progression occurred in 16% of the patients. In the asymptomatic group, ipsilateral stroke occurred more frequently (p = 0.0001) in patients with disease progression (25%) than in patients with stable lesions (1%). CFS detected disease progression in 19 (79%) of 24 patients before the artery occluded or stroke occurred. In patients with symptoms, stroke was more frequent (p = 0.02) in patients with six or more risk factors (29%) than in those with five or fewer risk factors (7%). CONCLUSION: Although the risk of stroke is less in patients with moderate stenosis than it is in patients with severely stenotic lesions, symptom-free patients with advancing disease and patients with symptoms and multiple risk factors are at increased risk for development of neurologic events. These findings support the use of CFS to monitor patients with carotid artery disease and suggest that a more aggressive surgical approach may be indicated in selected patients with moderate carotid artery stenosis.

Aged↗
PubMed1994

Color-flow duplex scanning of carotid arteries: new velocity criteria based on receiver operator characteristic analysis for threshold stenoses used in the symptomatic and asymptomatic carotid trials.

PURPOSE: Duplex scanning has become the standard for noninvasive evaluation of carotid arteries. However, current ultrasound criteria for internal carotid artery (ICA) stenosis (16% to 49%, 50% to 79%, 80% to 99%) may not be applicable to the categories (30% to 49%, 50% to 69%, 70% to 99%) used in ongoing symptomatic and asymptomatic carotid endarterectomy trials. This study was undertaken to determine new velocity criteria consistent with these categories. METHODS: From January 1, 1989 through October 30, 1992, 5871 color-flow duplex scans were obtained in our laboratories. After inadequate arteriograms and patients with a contralateral ICA occlusion were excluded, 770 peak systolic velocity (PSV) and 229 end-diastolic velocity (EDV) measurements were available for comparison with arteriography. ICA PSV and EDV were subjected to receiver operator characteristic curve analysis to determine optimum criteria for identifying stenoses of 30%, 50%, and 70%. RESULTS: For 70% to 99% carotid artery stenosis, PSV greater than 130 plus EDV greater than 100 provided the best sensitivity (81%), specificity (98%), positive predictive value (89%), negative predictive value (96%), and overall accuracy (95%). For 50% to 69% stenosis, a PSV greater than 130 and EDV of 100 or less cm/sec proved to be the best combination: sensitivity (92%), specificity (97%), positive predictive value (93%), negative predictive value (99%), and accuracy (97%). Stenoses in the 30% to 49% range were less accurately identified. CONCLUSION: These redefined criteria may prove useful for analyzing duplex ultrasound velocity data in reference to the classification of ICA stenosis used in recent clinical trials of the safety and efficacy of carotid endarterectomy.

Blood Flow Velocity↗
PubMed1994

Augmentation of blood flow in limbs with occlusive arterial disease by intermittent calf compression.

PURPOSE: This study was designed to investigate the effect of intermittent calf compression on popliteal arterial blood flow and to see how flow is influenced by position of the subject and by arterial blood pressure at the ankle. METHODS: Volume flow in the popliteal artery of subjects in the sitting and prone positions was measured with duplex ultrasonography before inflation and immediately after deflation of a pneumatic cuff placed around the calf. Eleven legs of control subjects and 41 legs of patients with symptoms (32% patients with diabetes) with decreased ankle pressure were studied. Cuffs were inflated for 2 seconds at pressures ranging from 20 to 120 mm Hg. RESULTS: An increase in arterial blood flow of two to eight times (mean 4.4 +/- 2.0) was found on deflation of the cuff in seated control subjects. Little change in flow was observed when the subjects were in the prone position. In seated patients with arterial obstruction, the mean increase in arterial flow was 3.2 +/- 1.6 times the resting flow. Little correlation was found between the maximum increase in flow and the ankle/brachial index. CONCLUSIONS: An increased arteriovenous pressure gradient accounts for some but not all of the flow increase, much of which must be attributable to transient vasodilatation. Because the increase in flow does not depend on an increased inflow pressure and was not adversely affected by a low resting ankle-brachial pressure index or a low toe-pressure, intermittent external limb compression may deserve investigation as a possible adjunct to the nonoperative treatment of patients with severe arterial insufficiency.

Adult↗
PubMed1994

Carotid endarterectomy without angiography: is color-flow duplex scanning sufficient?

BACKGROUND: This study was designed to determine whether clinical evaluation and color-flow duplex scanning (CFS) alone provide enough information for patients to undergo carotid endarterectomy (CEA) safely without preoperative cerebral angiography and to assess the appropriate role of CFS in the evaluation of extracranial carotid artery disease. METHODS: During a 31-month period 167 patients (114 symptomatic and 53 asymptomatic) underwent CFS and angiography during evaluation for CEA. One hundred fifty-three patients were studied retrospectively, and 14 were studied prospectively. Data were reviewed to determine whether cerebral angiography added information not provided by duplex findings and, if so, did the results alter clinical management. RESULTS: Of the 167 patients studied, 149 underwent CEA and 18 were treated medically. Results of the two diagnostic modalities agreed perfectly in 82% of the patients, with 99% of the stenoses estimated by CFS being classified within one category of those measured with angiography. The sensitivity of CFS for detecting greater than 50% diameter-reducing stenoses of the internal carotid artery was 98%, and the positive predictive value was 99%. For detecting greater than 80% stenoses, CFS had a sensitivity of 84% and a positive predictive value of 95%. Clinical management was altered by angiographic findings in only seven patients (4%). False-positive results (n = 5) were due to poor scanning technique or interpreter error (n = 2), anatomic variations (n = 2), and unknown cause (n = 1). All false-negative results (n = 2) were due to poor scanning technique. CONCLUSIONS: Ninety-six percent of the patients in this study would have received appropriate clinical management based on neurologic history and the results of CFS alone. Our results indicate that CFS is sufficient for determining the need for surgery in patients being considered for CEA and can supplant cerebral angiography in nearly all clinical circumstances.

Aged↗
PubMed1993

Does correction of stenoses identified with color duplex scanning improve infrainguinal graft patency?

PURPOSE: This study was undertaken (1) to determine whether correction of infrainguinal bypass stenoses detected with color duplex scanning (CDS) improved graft survival and (2) to define the natural history of grafts that did not undergo revision. METHODS: Over a 39-month period 462 color-flow duplex scans were obtained on 170 limbs with autogenous vein grafts. Grafts were scanned within 3 months of operation, at 6 and 12 months, and then yearly. Doubling of the velocity at any point in the graft-arterial system compared with the velocity immediately above or below (velocity ratio > or = 2.0) was the criterion adopted for identification of a hemodynamically significant (> or = 50%) diameter reduction. RESULTS: One hundred ten stenoses were detected in 62 (36%) of the limbs, of which 9 (8%) were in native vessels, 30 (27%) were at the anastomoses, and 71 (65%) were in the graft itself. Seventy-seven percent of the stenoses were detected in the first year. Twenty-four (39%) of the grafts with positive scans were revised. During follow-up, occlusions occurred in 10 (9%) of the 108 grafts with negative scans (NEG), in 2 (8%) of the 24 revised grafts with positive scans (PR), and in 10 (26%) of the 38 non-revised grafts with positive scans (PNR). Cumulative patency rates of NEG grafts were 90% at 1 year and 83% at 2 through 4 years. Similar patency rates were found in the PR vein grafts: 96% at 1 year and 88% at 2 through 4 years. In contrast, patency rates in PNR grafts with 50% or greater stenoses were only 66% at 1 year and 57% at 2 through 4 years. Log-rank tests showed a significant difference between the cumulative patency rates of NEG and PNR grafts (p < 0.002) and between PR and PNR grafts (p = 0.02). Flow velocities less than 45 cm/sec and ankle/brachial indexes did not discriminate well between grafts with or without 50% or greater stenoses or identify those grafts that subsequently occluded. CONCLUSIONS: The results of this study suggest that CDS detects graft-threatening lesions, that a velocity ratio of 2.0 or greater is the most highly predictive parameter, and that revision of grafts with stenoses identified with CDS prolongs patency.

Adult↗
PubMed1993

Does air plethysmography correlate with duplex scanning in patients with chronic venous insufficiency?

PURPOSE: Duplex ultrasonography with distal cuff deflation was used to determine the presence and size of incompetent veins and compare the results with those of air plethysmography in patients with chronic venous insufficiency. METHODS: Thirty-two legs underwent a detailed study with both modalities. Sixteen legs had venous ulceration, six had stasis dermatitis, and ten had symptomatic varicose veins without skin changes. RESULTS: Although the venous filling index (VFI) in limbs with ulcers (5.4 +/- 3.8 ml/sec) and dermatitis (7.7 +/- 4.6 ml/sec) was significantly higher (p < 0.05) than it was in limbs with varicose veins (2.6 +/- 1.7 ml/sec), there was a large amount of overlap. Only 13% of ulcerated legs had VFI greater than 10 ml/sec. Sixty-three percent of legs with ulcers, 33% of legs with dermatitis, and 90% of legs with varicose veins had VFIs less than 5 ml/sec. Mean ejection fractions (EFs) in the three groups were similar, ranging from 45% to 52%. Combining VFI and EF did not lessen the overlap between groups. Forty-one percent of limbs with ulcers or dermatitis had air plethysmography parameters in the normal or intermediate area (VFI < 5 ml/sec; EF > 40%), which in previous studies corresponded to an incidence of ulceration of only 2%. VFI had a significant but weak correlation (r = 0.39) with the diameter of incompetent veins at the knee and a somewhat stronger relationship (r = 0.55) with the diameter of lower leg veins. Total venous volume correlated moderately well with calf vein diameter (r = 0.75). The clinical status of the leg did not correlate with the diameters of incompetent veins at the knee or calf levels. All limbs with an obstructed outflow had EFs less than 60% and ulcers or dermatitis. CONCLUSIONS: We conclude that plethysmographic measurements of functional venous parameters (VFI,EF) do not discriminate well between limbs with uncomplicated varicose veins and limbs with ulcers or stasis dermatitis and that VFI correlates poorly with the presence of incompetent veins and their diameters. Both duplex scanning and plethysmography seem to be necessary for a complete evaluation of limbs with chronic venous insufficiency.

Chronic Disease↗
PubMed1993

Presentation and natural history of internal carotid artery occlusion.

PURPOSE: This retrospective study was undertaken to investigate the effect of presenting neurologic symptoms, vascular risk factors, and degree of contralateral internal carotid artery stenosis on subsequent stroke and death rates of patients with internal carotid artery occlusion (ICO). METHODS: One hundred sixty-seven patients with ICO were evaluated over a 5-year period. Mean follow-up was 39 months. Initial symptoms included transient ischemic attack in 29 patients (17%), stroke in 71 patients (43%), nonhemispheric symptoms in 22 patients (13%), and no symptoms in 45 patients (27%). Ninety percent of the presenting strokes occurred ipsilateral to the ICO. RESULTS: During follow-up 54 (32%) patients died, 10 (19%) of stroke and 22 (41%) of heart disease. The 5-year cumulative survival rate was 63%. Subsequent neurologic events occurred in 26% of the patients. Thirty patients (18%) had a stroke during follow-up, of which 20 (67%) occurred ipsilateral to the ICO. The 5-year stroke-free rate was 76%. Patients who had a stroke had a less favorable 4-year stroke-free rate (67%) than those who had transient ischemic attack (92%) or those who originally had no symptoms (89%), p = 0.03 and p = 0.04, respectively. In addition, there was a trend towards a worse 5-year contralateral stroke-free rate in patients with contralateral stenosis of 50% to 99% (77%) compared with patients with less than 50% contralateral stenosis (94%), p = 0.08. Twenty patients underwent carotid endarterectomy on the nonoccluded side. There were no perioperative strokes or deaths. Carotid endarterectomy seemed to reduce the long-term stroke morbidity rate (p = 0.10) on the operated side in patients with 80% to 99% contralateral stenosis but did not perceptibly improve stroke-free rates on the occluded side or in patients with 50% to 79% stenosis. CONCLUSION: Patients with ICO have a variable prognosis. There is a significant incidence of subsequent stroke, which seems to be related to the presenting neurologic event and the degree of stenosis in the contralateral internal carotid artery.

Adult↗
PubMed1993

Routine surveillance after carotid endarterectomy: does it affect clinical management?

PURPOSE: Although routine noninvasive surveillance is recommended after carotid endarterectomy (CEA), there are little data to show that identification and eradication of recurrent carotid artery stenosis are necessary to avoid the risk of subsequent neurologic complications. METHODS: We reviewed our experience over a 16-year period in 380 consecutive patients undergoing 409 CEAs who underwent serial postoperative ultrasonic scanning at 6 weeks, 6 months, and 1 year after CEA and then yearly thereafter. RESULTS: Recurrent stenoses (> or = 50% diameter reduction) were detected in 44 arteries (10.8%) during follow-up from 1 to 177 months (mean 42.0 months). Most (70.5%) occurred within 2 years of CEA. Cumulative recurrence rates were 5.8%, 9.9%, 13.9%, and 23.4% at 1, 3, 5, and 10 years, respectively. Recurrent stenoses were more frequent in female (p = 0.02) and younger patients (p = 0.01) and less frequent in those having a vein patch repair (p = 0.02). Most recurrences (84%) were in the 50% to 79% stenosis range. In four patients 80% to 99% stenoses developed and in three patients total occlusions developed, for a severe recurrence rate of 2.1%. Only 10 (22.7%) of the recurrent stenoses were initially symptomatic, and only one (2.9%) of the asymptomatic restenoses later became symptomatic. One patient with recurrent stenosis suffered a stroke (0.3%). Cumulative 5-year ipsilateral stroke-free rates in patients with recurrent stenosis (94.4%) were practically identical (p = 0.76) to those in patients without recurrent stenosis (94.2%). Life-table ipsilateral stroke-free survival rates at 5 years were 94.2% in patients with recurrent stenosis and 78.4% in patients without recurrent stenosis (p = 0.16). Four (9%) recurrent stenoses and 12 lesions (27%) in the contralateral artery progressed. Only seven patients (1.7%) underwent repeat operation for ipsilateral disease, four for symptoms and three for recurrent stenosis. CONCLUSIONS: Recurrent carotid artery stenosis occurs early after CEA, is typically benign, and remains stable over a prolonged follow-up period. Our results question the importance of routine noninvasive surveillance after CEA and suggest that a more conservative approach would be equally beneficial in terms of clinical relevance and cost-effectiveness.

Aged↗
PubMed1993

The influence of carotid siphon stenosis on short- and long-term outcome after carotid endarterectomy.

PURPOSE: This study was designed to determine whether the presence of ipsilateral carotid siphon stenosis influenced the risk of early and late stroke and death after carotid endarterectomy (CEA). METHODS: The outcomes of patients with moderate (20% to 49%), severe (> 50%), and no siphon stenosis were compared over a 16-year period from April 1976 to February 1992. Complete angiographic data were available in 393 carotid arteries. RESULTS: Siphon stenosis was found ipsilateral to the CEA in 84 (21.4%) of the arteries. Most lesions were in the 20% to 49% diameter-reducing range (77.4%), with the remainder in the greater than 50% range (22.6%). There were no occlusions. The perioperative mortality rate was nearly identical for the groups with and without siphon stenosis, 0.0% versus 0.6%, respectively (p = 0.99). Perioperative stroke morbidity rates (no stenosis, 2.3%; moderate stenosis, 3.1%; > 50% stenosis, 5.3%) were acceptable and were not statistically different (p > 0.38). Late ipsilateral stroke-free rates were similar in the groups with and without siphon stenosis. The 5- and 7-year stroke-free incidences were 88.5% and 83.4% versus 94.9% and 94.9%, respectively (p > 0.20) for the two groups. Long-term ipsilateral stroke-free rates were not significantly different in the subgroups with moderate (20% to 49%) and hemodynamically significant (> 50%) siphon stenosis. The 3- and 5-year ipsilateral stroke-free rates were 96.7% and 87.9% versus 94.6% and 94.6%, respectively (p = 0.69). Late death was more common in the group with siphon stenosis than it was in the group without siphon stenosis, 23.8% versus 12.5% (p = 0.02). Heart disease was responsible for most late deaths, 47% in both groups. Late stroke-related deaths were infrequent: 1.3% in patients with and 0.0% in patients without siphon stenosis. CONCLUSIONS: Although carotid siphon stenosis seemed to be associated with a higher risk of late death, it did not alter the short- and long-term stroke morbidity rates after carotid endarterectomy significantly. We conclude that the presence of carotid siphon stenosis should not influence the decision to perform carotid endarterectomy in patients with the appropriate indications.

Aged↗
PubMed1992

Identifying total carotid occlusion with colour flow duplex scanning.

A major limitation of conventional duplex scanning is its inability reliably to differentiate severe stenosis from total occlusion of the internal carotid artery (ICA). Colour flow duplex scanning (CFS) facilitates the identification of internal and external carotid arteries, enables simultaneous evaluation of flow in multiple vessels in longitudinal and transverse views, and allows more accurate assessment of very low Doppler-shift frequencies with new "slow-flow" software technology. From July 1987 to January 1991, 9731 ICAs (4866 patients) were evaluated with CFS. Arteriography was performed in 483 of these patients (959 ICAs), and the results of the two studies were compared. Colour flow scanning was highly accurate in differentiating total occlusion from carotid stenosis. Eighty-two of 87 totally occluded ICAs were detected (sensitivity 94%) and 873 of 878 patient arteries were properly identified (specificity 99%). Positive and negative predictive values were 93 and 99%, respectively. False positive results (n = 6) were due to interpreter error (n = 4) and poor scanning technique (n = 2). All false negative results (n = 5) were the result of interpreter error. During the last 24 months of the study, no false positive or false negative results were detected, giving an accuracy of 100%. We conclude that CFS offers distinct advantages in the diagnosis of carotid occlusion, thereby overcoming the limitations of conventional duplex scanning in distinguishing total occlusion of the ICA from less severe disease, and is the method of choice for evaluating the carotid bifurcation.

Arterial Occlusive Diseases↗
PubMed1992

Color-flow duplex scanning for the surveillance and diagnosis of acute deep venous thrombosis.

Compared with conventional duplex imaging, color-flow scanning facilitates the identification of veins (especially below the knee), decreases the need to assess Doppler flow patterns and venous compressibility, and allows veins to be surveyed longitudinally. These advantages translate into a less demanding and time-consuming examination. This study was designed to determine the accuracy of color-flow scanning for detecting acute deep venous thrombosis in patients in whom the diagnosis is clinically suspected and in asymptomatic patients at high risk for developing postoperative deep venous thrombosis. The diagnostic group included 77 limbs of 75 patients, and the surveillance group included 190 limbs of 99 patients undergoing total hip or knee replacement. All patients were prospectively examined with color-flow scanning and phlebography. In the diagnostic group, the incidence of thrombi in below-knee veins (47%) was approximately equal to that in above-knee veins (43%); but in the surveillance group, the incidence of thrombi in below-knee veins (41%) far exceeded that in veins above the-knee (3%). Nonocclusive clots and clots isolated to a single venous segment were more common in the surveillance group. In symptomatic patients, color-flow scanning was 100% sensitive and 98% specific above the knee and 94% sensitive and 75% specific below the knee. In the surveillance group, color-flow scanning was significantly (p less than 0.001) less sensitive (55%) for detecting thrombi, 93% of which were confined to the tibioperoneal veins. Negative predictive values were 100% and 88% for the diagnostic and surveillance limbs, respectively. Positive predictive values were 80% for the diagnostic limbs and 89% for the surveillance limbs. Color-flow scanning effectively excludes above-knee deep venous thrombosis in symptomatic patients and asymptomatic high-risk patients and predicts the presence of above-knee thrombi in patients in the diagnostic group with reasonable accuracy (97%). We conclude that color-flow scanning is as accurate as conventional duplex imaging and, because of its advantages, is the noninvasive method of choice for evaluating patients with suspected deep venous thrombosis. Its role in the surveillance of patients at high risk remains to be determined and awaits further clinical evaluation.

Acute Disease↗
PubMed1992

Internal carotid artery occlusion: operative risks and long-term stroke rates after contralateral carotid endarterectomy.

BACKGROUND: To determine the short- and long-term benefits of carotid endarterectomy (CEA) contralateral to an occluded internal carotid (ICA), we reviewed our experience since 1976. METHODS: In 66 (13.8%) of 478 patients undergoing 544 CEAs, the contralateral ICA was occluded. Mean follow-up was 50.1 months (range, 1 to 165 months). Complete follow-up was available in 83.0% of patients. RESULTS: Operative death occurred in one (1.5%) of 66 patients with contralateral occlusion and six (1.3%) of 478 patients without contralateral occlusion (p = 0.99). Operative strokes occurred in two (3.0%) of 66 patients with contralateral occlusion and 14 (2.9%) of 478 without contralateral occlusion (p = 0.99). Life-table stroke-free rates at 1, 3, 5, and 8 years were 96.8%, 93.0%, and 93.0% in patients with contralateral occlusion and 95.9%, 94.2%, 91.1%, and 88.0% in patients without contralateral occlusion (p = 0.36). Five- and 8-year stroke-free rates were 100% and 100% in the asymptomatic subgroup with occlusion, 95.9% and 92.2% in the asymptomatic subgroup without occlusion (p = 0.45), 91.2% and 91.2% in the symptomatic subgroup with occlusion, and 89.7% and 86.8% in the symptomatic subgroup without occlusion (p = 0.47). Life-table survival rates at 5 and 8 years were 72.5% and 56.0% in patients with contralateral occlusion and 81.8% and 69.0% in patients without contralateral occlusion (p = 0.15). CONCLUSIONS: CEA performed in patients with and without symptoms with a contralateral ICA occlusion produces short- and long-term mortality and stroke morbidity rates comparable to those of similar patients without contralateral ICA occlusion. The indications for CEA in patients with contralateral ICA occlusion should not differ from those applied to patients without contralateral occlusion.

Aged↗
PubMed1991

Infrapopliteal bypass for severe ischemia: comparison of autogenous vein, composite, and prosthetic grafts.

Results of 253 consecutive bypass grafts to infrapopliteal arteries were reviewed. Most (92%) were placed for rest pain (103) or tissue loss (130). Autogenous veins were used in 175 (69%) cases, composite vein-prosthetic grafts were used in 45 (18%), and prosthetic grafts alone were used in 33 (13%). Follow-up ranged from 0 to 101 months (mean, 19 months); 37 grafts (15%) were lost to follow-up. The operative mortality rate was 4%, and 5-year patient survival rate was 44%. Limb salvage was 82% at 5 years. The 5-year patency of vein grafts (63%) exceeded that of both composite (28%) and prosthetic (7%) grafts (p = 0.005 and p = 0.00007, respectively); but the patency of composite and prosthetic grafts did not differ significantly (p = 0.29). The patency of reversed vein (59%) and in situ vein grafts (74%) was not significantly different at 5 years (p = 0.34). Patency was also not affected by the site of the proximal or distal anastomoses or diabetes. The major determinant of long-term patency in infrapopliteal reconstructions continues to be graft material. Composite grafts offered no clear advantage over prosthetic grafts, and both should be used only when there is no other alternative to amputation.

Adult↗
PubMed1991

Does color-flow imaging improve the accuracy of duplex carotid evaluation?

To determine whether color-flow imaging enhances the accuracy of noninvasive carotid evaluation, the results of carotid duplex examinations from two laboratories, one with color-flow and the other with standard duplex imaging were compared. The techniques used by both laboratories were identical. All studies were interpreted by one of the authors, using the same criteria. From October 1988 through December 1989, 307 internal carotid arteries were evaluated with both color-flow imaging and standard angiography; and 206 underwent routine duplex scanning and angiography. Perfect agreement between test and angiographic results was significantly better with color-flow (86.6%) than with conventional duplex scanning (79.6%), p = 0.034 (t test for independent samples). Significantly fewer vessels were over classified by one category with color-flow (8.5%) than with routine duplex scanning (16.5%), p = 0.006. However, no difference was found in the number under-classified by one category (4.5% vs 3.4%), p = 0.5. Although these data support the accuracy of both modalities, there appears to be a trend toward improved results with the newer method. We attribute this to more precise placement of the pulsed Doppler sample volume afforded by the color-flow image.

Angiography↗
PubMed1990

Use of color-flow imaging technique in carotid artery disease.

Color-flow imaging of the cervical vasculature has several distinct advantages compared with conventional duplex scanning: it facilitates identification of the carotid artery, its bifurcation, branches, and other cervical vessels, especially the vertebral arteries; decreases the time required for longitudinal surveys; aids in the recognition of kinks, coils, and occluded vessels; evaluates flow simultaneously in large areas and multiple vessels; and focuses attention on sites of flow disturbance. Although many problems remain, color-flow imaging represents a powerful new tool for the diagnosis and physiologic assessment of extracranial cerebrovascular disease.

Blood Flow Velocity↗