cerebral ischemic stroke is a major cause of death , ranking third behind only malignancies and cardiovascular disease . atherosclerosis of the intra and extracranial carotid vessels , leading to cerebral infarction accounts for 80% of strokes . intracranial hemorrhage and subarachnoid hemorrhage account for the remainder . it has been conclusively proven that the risk of major stroke is higher in the first 3 months after transient ischemic attack ( tia ) . it has been seen that 20% or more of strokes have been heralded by a tia . the highest risk of large artery stroke appears to be among patients with the highest degree of carotid stenosis , a history of diabetes , presence of asymptomatic carotid plaques , or a combination of these factors . color doppler sonography of carotid arteries forms an important part of the evaluation of extracranial insufficiency . accurate diagnosis of hemodynamically significant stenosis is critical to identify patients who would benefit from surgical intervention . the value of a safe , noninvasive , and low - cost screening test is therefore of a great advantage . duplex sonography combining high - resolution imaging and doppler spectrum analysis has proved to be a popular , noninvasive , accurate , and cost - effective means of detecting and assessing carotid disease . if timely endarterectomy of the carotid arteries is performed , many stroke cases may be prevented . carotid conventional angiography is the gold standard for detecting the severity of carotid stenosis , but it has its own disadvantages such as it is an invasive and expensive procedure . it carries a risk from contrast medium to the patients and a certain amount of morbidity . magnetic resonance angiography is currently developing rapidly and may ultimately give similar or better results , especially for flow quantification , though at a much higher cost . besides estimating the degree of stenosis , the biggest advantage of sonography is its ability to characterize plaque and identify plaques with higher risk of embolization . with high - resolution ultrasound , plaque can be characterized into relative risk groups containing intraplaque hemorrhage which is thought to be a precursor for plaque ulceration . the brain is supplied by four vessels : the two internal carotid arteries ( icas ) and the two vertebral arteries [ figure 1 ] . this study was done to assess the carotid arteries with the help of color doppler sonography and to correlate cerebrovascular accidents ( cvas ) with extracranial carotid artery status . this descriptive study was carried out on 50 patients who had symptoms and signs of a stroke or tias at a tertiary care hospital in south india for a period of 2 years . patients were selected using purposive sampling technique without any age , sex , ethnic , or socioeconomic discrimination . risk factors such as hypertension , diabetes mellitus , smoking , and ischemic heart disease were documented . the patients underwent computed tomography ( ct ) scan study prior to the color doppler sonography of carotid arteries and findings were documented . cases with history , clinical and ct scan findings consistent with cerebral ischemic stroke were included in this study . patients having symptoms suggestive of vertebrobasilar insufficiency , head injuries , and those having primary and metastatic brain tumors were excluded from the study . the data gathered from the ct scan examination consisted of : side of the infarct middle cerebral artery , anterior cerebral artery , posterior cerebral artery ; cortical or subcortical infarct time interval between the onset of clinical signs / symptoms of ischemic stroke and ct scan performed . the data gathered from the color doppler examination consisted of : peak systolic velocity ( psv ) of common carotid artery ( cca ) and ica ; ica / cca velocity ratios ; plaque characteristics ; the presence of spectral broadening ; and detection and grading of carotid artery stenosis . all the examinations were performed by the same operator with a doppler angle of 60. color doppler sonography was done using philips envisor c ( philips medical systems , nederland b.v . ) with a linear array transducer of 7 mhz . prior ct scan was performed using ge bright speed elite , 16 slice ct scanner ( ge healthcare , milwaukee , wi , usa ) . ( a ) ica / cca psv ratios , and ( b ) residual lumen diameter at most stenotic portion was compared to lumen diameter in the ica bulb as used in asymptomatic carotid atherosclerosis study . the diameter of the residual lumen and the external diameter of the artery at the same level were measured and the degree of stenosis was calculated using the relationship : percent stenosis = ( d  d ) 100/d , where d is vessel wall - to - wall diameter and d , is patent vessel diameter . the gold standard has been angiography and the parameter that angiography provides is diameter stenosis and hence , in ultrasound , we also used diameter stenosis . the collected data were analyzed with the aid of a calculator and presented in the form of tables , figures , graphs , and diagrams wherever necessary . the findings are discussed in the light of findings of other similar studies . as this study deals with the only frequency distribution of various factors , so the data gathered from the ct scan examination consisted of : side of the infarct middle cerebral artery , anterior cerebral artery , posterior cerebral artery ; cortical or subcortical infarct time interval between the onset of clinical signs / symptoms of ischemic stroke and ct scan performed . the data gathered from the color doppler examination consisted of : peak systolic velocity ( psv ) of common carotid artery ( cca ) and ica ; ica / cca velocity ratios ; plaque characteristics ; the presence of spectral broadening ; and detection and grading of carotid artery stenosis . color doppler sonography was done using philips envisor c ( philips medical systems , nederland b.v . ) with a linear array transducer of 7 mhz . prior ct scan was performed using ge bright speed elite , 16 slice ct scanner ( ge healthcare , milwaukee , wi , usa ) . ( a ) ica / cca psv ratios , and ( b ) residual lumen diameter at most stenotic portion was compared to lumen diameter in the ica bulb as used in asymptomatic carotid atherosclerosis study . the diameter of the residual lumen and the external diameter of the artery at the same level were measured and the degree of stenosis was calculated using the relationship : percent stenosis = ( d  d ) 100/d , where d is vessel wall - to - wall diameter and d , is patent vessel diameter . the gold standard has been angiography and the parameter that angiography provides is diameter stenosis and hence , in ultrasound , we also used diameter stenosis . the collected data were analyzed with the aid of a calculator and presented in the form of tables , figures , graphs , and diagrams wherever necessary . the findings are discussed in the light of findings of other similar studies . as this study deals with the only frequency distribution of various factors , so among the 50 patients , 36 patients ( 72% ) were males and 14 ( 28% ) were females . of the 50 patients studied , 20 ( 40% ) patients had right - sided stroke and 18 ( 36% ) patients had left - sided stroke . bilateral involvement was seen in 2 ( 4% ) patients and 10 ( 20% ) patients had tia . of the 12 patients with significant stenosis ( > 60% stenosis ) , the maximum patients were seen in the age group of 6069 years that is 6 ( 50% ) patients . next age group was of 7079 years with 4 ( 33.3% ) patients . in age group 40 - 49 years and > 80 smoking and hypertension were the most prevalent risk factors for cerebral ischemic stroke [ figure 2 ] . risk factors of cerebral ischemic stroke ct brain findings showed normal findings in 13 cases , whereas lacunar infarcts ( 13 cases ) were the most common pathological involvement [ table 1 ] . ct brain findings in stroke patients of the 12 patients with significant stenosis , none of the patients showed bilateral involvement . eight ( 66.6% ) patients had right - sided involvement and 4 ( 33.3% ) patients had left - sided involvement . seven patients have 6079% occlusion , 3 patients have 8089% occlusion whereas 2 patients have complete occlusion [ figure 3 ] . of the total 39 patients with occlusion , 27 patient with significant stenosis ( > 60% ) atherosclerotic changes in the form of atheromatous plaques were found to be the main cause of obstruction . of the 39 patients having plaque in the extracranial carotid system , 23 ( 59% ) patients had bilateral involvement , 9 ( 24% ) patients had plaque on right side and 7 ( 17% ) patients had plaque on the left side . the remaining 11 ( 22% ) patients out of 50 showed no evidence of plaque . in our study plaques in the cca were also seen on the right side in 1 patient and 1 on the left side . the bilateral homogenous plaque was the most commonly seen type of plaque [ figure 5 ] . site distribution of plaque ( cca : common carotid artery , ica : internal carotid artery ) plaque characterization of the 39 cases having carotid plaques , 2 cases were ( 5.1% ) found to have a total block in which the psv ratio was not applicable . distribution of cases having carotid plaques , based on psv ratio of ica / cca is shown in figure 6 . distribution of cases having carotid plaques based on peak systolic velocity ratio of internal carotid artery / common carotid artery about 3060% of strokes are caused by atherosclerotic disease involving the extracranial carotid arteries usually within 2 cm of the carotid bifurcation . sonographically detected plaque characteristics may have prognostic value and may be useful for selection of medical and surgical therapy . this study was done to evaluate the extracranial carotid arterial system in the patients who presented with cerebral ischemic stroke and correlated cva with extracranial carotid artery status . in an earlier study , it was found that the incidence of stroke increases after 60 years of age . the highest number of stroke patients in our study were found in the age group of 6069 years which was 32% ( 16/50 ) , followed by the age group between 70 and 79 years which was 26% ( 13/50 ) . iemolo et al . in his study showed that only 2.5% of stroke victims were females . in this study , 72% of the patients ( 36/50 ) were males and only 28% of the patients were females ( 14/50 ) . studied 188,000 patients with hypertension out of which 6800 had stroke events . in our study , of the 50 patients , 19 ( 38% ) patients were hypertensive out of which 4 ( 21% ) had significant stenosis . it was estimated in an earlier study that 22% of stroke was attributable to smoking . a study conducted by lindsberg and roine observed that two - third of all ischemic stroke types on admission had diabetes mellitus . in this study , 8 ( 16% ) patients had diabetes mellitus of which 3 ( 37% ) had significant stenosis . schulz et al . studied the family history of stroke and found that 23% of stroke patients had a positive family history . in this study , family history of stroke was present in 7 ( 14% ) patients of which 3 ( 42% ) had significant stenosis . cardiac diseases were ruled out in our patient since they interfere in the velocity profiles of the carotid system . normal cca color doppler waveform is shown in figure 7 . in the literature of ultrasound , different authors say that one of the 3 major doppler parameters that is , psv , edv , or psv ratio is the most accurate predictor of clinically significant ica stenosis . because a ratio compensates for the patient to patient physiological variability and also compensate for instrument variability , psv ratio has been considered best for assessing stenosis . north american symptomatic carotid endarterectomy trial and european carotid endarterectomy trial clearly demonstrated that the long - term benefits of endarterectomy were significantly greater than medical treatment in patients with 60% or 70% ica stenosis , whether symptomatic , or asymptomatic . second , the endarterectomy trials established 6070% diameter reduction as clinically significant levels of ica stenosis . normal left common carotid artery color doppler waveform in a 45-year - old male with a history of transient ischemic attack and normal brain computed tomography scan study psv ratio of > 1.8 is an indicator of 60% or greater and a ratio of 3.7 is an indicator of more than 80% diameter stenosis . the validity of 1.5 ratio of psv ratio of ica / cca is an indicator of 50% or greater stenosis . it has been found that the ratio is more accurate than psv . using the criteria of ica / cca ratio , of the 10 patients with significant stenosis , 7 ( 70% ) had significant stenosis on right side and 3 ( 30% ) had significant stenosis on left side . on the right side on the left side , 1 patient had 6079% stenosis and 2 patients had 80 - 99% stenosis . the duplex imaging of complete carotid occlusion was based on the absence of arterial pulsation , lumen filled with echogenic material , subnormal vessel size , and the absence of doppler flow signals or weak doppler signals . in this study , we came across 2 patients with complete occlusion , 1 on the left and other on the right side . severely stenosed contralateral ica can artificially elevate ultrasound psv since the effect was greatest when bilateral severe stenosis was present . caution must be exercised when assessing the degree of ica stenosis on the basis of ultrasound psv alone . we came across 1 patient who showed bilateral involvement with increased psv > 130 on the contralateral side . he also confirmed his findings by postmortem studies . in our study , 39 ( 78% ) patients had plaques in the carotid artery of which 9 patients had plaques on the right side , 7 patients had plaques on the left side and 23 patients had bilateral involvement . carotid bifurcation is commonly involved by the atherosclerotic plaque located distal to the origin of the carotid arteries . in our study , ica was found to be the commonest site affected by the plaque in 9 patients . in the present study , 12 patients had calcified plaques , 16 patients with strongly echogenic plaque , 7 had moderate echogenic plaque , and 4 patients showed low echogenic plaque . soft plaques and heterogeneous plaques more positively correlate with symptoms than with any degree of stenosis and were the cause of adverse neurological events . intraplaque hemorrhages are associated with frank ulceration and rapid progression to result in severe luminal narrowing . among the 4 low echogenic plaque lesions noted in our study , we came across 16 hyperechogenic plaques , and most of them were suggestive of very old thrombi . calcification occurs in plaque [ figure 8 ] in the areas of hemorrhage and necrosis . the risk of embolization or rapid progression would depend on plaque composition especially if it was heterogeneous , diffuse , or focal . figure 9a shows soft plaque in left ica 58.9% diameter stenosis and figure 9b shows soft plaque in left ica 31% diameter stenosis . carotid artery stenosis of 70% or more was diagnosed reliably with the following duplex ultrasound criteria that is , a psv of 230 cm / s or more and end diastolic velocity of 70 cm / s or more , or an ica : cca ratio of 3.2 or more in previous study . in our study , we found 2 patients having psv of ica > 230 cm / s . both the patients found to have > 80% stenosis . using ica / cca ratio criteria , 10 patients had significant stenosis ( ratio > 1.8 ) in which 3 patients had ica / cca ratio > 3.7 . two patients had complete occlusion on each side where no flow was detected in the vessel , hence , ica / cca ratio could not be assessed in them [ figure 10 ] . calcific plaque at common carotid artery bifurcation in a 789-year - old female with a history of diabetes mellitus having lacunar infarcts in bilateral corona radiata ( a ) soft plaque in right carotid bulb with 58.9% stenosis in a 64-year - old male having right middle cerebral artery territory infarct . ( b ) soft plaque in same patient with 31% stenosis in left proximal internal carotid artery complete occlusion of left internal carotid artery with hypoechoic plaque in a 72-year - old male with left middle cerebral artery territory infarct a study conducted by von jessen and sillesen showed that duplex scanning in 17% of patients who had tia were found to have stenosis of 50% or greater and for the patient with persistent central neurological symptoms ( stroke ) , stenosis was found in 50% . we came across 12 patients with significant ( > 60% ) stenosis of which 5 ( 41.6% ) patients had hemiplegia , 6 ( 50% ) patients had hemiparesis , and 1 ( 8.3% ) patient had tia . in our study consisting of 50 patients with cerebral ischemic stroke , carotid plaque was found in 39 ( 78% ) patients . according to a study conducted by seth et al . all patients with > 40% stenosis had a cortical infarct , none of the patients with > 40% stenosis had a subcortical infarct . all with subcortical infarcts had either normal extracranial carotids or had < 40% stenosis . in our study , out of 12 patients with significant stenosis ( > 60% ) , 7 ( 58.3% ) patients had cortical infarct , 1 ( 8.3% ) patient had subcortical infarct , and 4 ( 33.34% ) patients showed normal study . of 39 patients with < 60% carotid stenosis , 12 ( 30% ) were found to have cortical infarct , 12 ( 30% ) had subcortical infarct , and 15 ( 38% ) showed normal findings on ct scan study . no histopathological correlation was done in our study because surgery was not done in any of the above patients . the role of carotid doppler in detecting the site and morphology of atherosclerotic plaque and quantifying the degree of stenosis is very well justified .
aims and objectives : cerebral ischemic stroke is life - threatening and debilitating neurological disease , it is the third leading cause of death in the world . 
 studies have shown that there is a close relationship between carotid artery stenosis and ischemic cerebral vascular disease . 
 this study is done to assess the carotid arteries with the help of color doppler sonography and to correlate cerebrovascular accidents.materials and methods : the prospective study was carried out on 50 patients using purposive sampling technique . 
 risk factors such as hypertension , diabetes mellitus , smoking , and family history were documented . 
 the data gathered from color doppler examination consisted of peak systolic velocity of common carotid artery ( cca ) and internal carotid artery ( ica ) , velocity ratios between cca and ica and plaque characteristics as seen on real - time image.statistical analysis used : the collected data were analyzed and presented in the form of tables , figures , graphs , and diagrams wherever necessary . as this study deals with the only frequency distribution of various factors , 
 so no tests of significance were applied.results:the highest incidence of stroke was found in the male population in the age group of 6069 years . 
 various risk factors included hypertension , diabetes mellitus , smoking , and family history . 
 of 50 patients , 12 patients showed significant stenosis ( > 60% ) . 
 atherosclerotic plaques were seen in 39 patients ( 78%).conclusion : color doppler examination is an economic , safe , reproducible , and less time - consuming method of demonstrating the cause of cerebrovascular insufficiency in extracranial carotid artery system and will guide in instituting treatment modalities .