Transcranial Doppler ultrasonography: From methodology to major clinical applications

Non-invasive Doppler ultrasonographic study of cerebral arteries [transcranial Doppler(TCD)] has been extensively applied on both outpatient and inpatient settings. It is performed placing a low-frequency(≤ 2 MHz) transducer on the scalp of the patient over specific acoustic windows, in order to visualize the intracranial arterial vessels and to evaluate the cerebral blood flow velocity and its alteration in many different conditions. Nowadays the most widespread indication for TCD in outpatient setting is the research of right to left shunting, responsable of so called "paradoxical embolism", most often due to patency of foramen ovale which is responsable of the majority of cryptogenic strokes occuring in patients younger than 55 years old. TCD also allows to classify the grade of severity of such shunts using the so called "microembolic signal grading score". In addition TCD has found many useful applications in neurocritical care practice. It is useful on both adults and children for day-to-day bedside assessment of critical conditions including vasospasm in subarachnoidal haemorrhage(caused by aneurysm rupture or traumatic injury), traumatic brain injury, brain stem death. It is used also to evaluate cerebral hemodynamic changes after stroke. It also allows to investigate cerebral pressure autoregulation and for the clinical evaluation of cerebral autoregulatory reserve.

Transcranial Doppler Ultrasonography to Prevent Cerebrovascular Accident in Children with Sickle-Cell Disease

Sickle-cell disease (SCD) is the most common cause of ischemic stroke in children and it happens in about 11% of patients between the age of 2 and 20 years old. About 7% of the world population is affected by hemoglobin disorders, mostly sickle cell anemia. SCD has a high prevalence in the population of African offspring and it is a public health problem in Brazil that affects more than 30,000 million people. Prevention of primary stroke might be feasible with a way to identify children at greatest risk. Transcranial Doppler Ultrasonography (TCD) to SCD patients can be a valuable service that results in a significant decrease of first stroke rates. In this work, we present a review about TCD as an effective strategy to detect children with SCD who are at risk for stroke.

Nitrogen monoxide vector of ultrasonic atomizing inhalation improves vertebro-basilar artery insufficiency Hemodynamic changes are detected by transcranial Doppler test

BACKGROUND： Latest researches at home and abroad indicate that glycerol trinitrate plays its function because it can metabolize into nitrogen monoxide （NO） in vivo. OBJECTIVE： To study the therapeutic effects of NO vector of ultrasonic atomizing inhalation on vertebro-basilar artery insufficiency （VBI） through transcranial Doppler （TCD） detection and serum NO content and indirect effect of TCD on cerebral blood flow changes. DESIGN： Randomized grouping and controlled clinical study. SETTING： Department of Neurology, the Fourth People＇s Hospital of Jinan. PARTICIPANTS： A total of 130 patients who were diagnosed as VBI were selected from Department of Neurology, the Fourth People＇s Hospital of Jinan from December 2001 to December 2005. The involved inpatients were checked by CT and MRI, and met the VBI diagnostic standard enacted by the Fourth National Academic Meeting of Cerebrovascular Disease in 1995. All patients and their relatives provided the confumed consent. They were randomly divided into low-dose treatment group （n =60）, high-lose treatment group （n =30） and control group （n =40）. METHODS： Patients in the low-dose and high-dose treatment groups were given ultrasonic atomizing inhalation of 3 mg and 5 mg glycerol trinitrate, respectively, for 20 minutes, once a day. In addition, ligustrazine and energy mixture were used once a day for three days in a course. Cases in the control group were only given ligustrazine and energy mixture. All selected cases accepted TCD, blood NO content was checked at the time of beginning, after the first time and after a period of treatment. According to the TCD test, VBI patients were divided into two groups （high-low flow velocity）. The vertebral artery （VA） and basal artery （BA） of left or right sides were detected by 2 Hz detector via occipital window. MAIN OUTCOME MEASURES： ①Blood flow velocity of systolic phase, blood flow velocity of diastole phase and vascular resistance in left and right VA and BA detected by using TCD before treatment, after treatment for one course; ②content of serum NO indirectly measured by using nitric acid disoxidation technique. RESULTS： All 130 VBI patients were involved in the final analysis. ①Changes of hemodynamic indexes： Systolic phase of VA and diastole phase of BA were higher in low-dose treatment group than that in the control group after first treatment, and there was significant difference （P 〈 0.05）; meanwhile, systolic phase and diastole phase of VA and systolic phase of BA were also higher in treatment group than that in the control group after one course （P 〈 0.05）. However, both systolic phase and diastole phase of VA and BA were lower in high-dose treatment group than that in the control group after first treatment and one course, and there was significant difference （P 〈 0.05）. ②Content of serum NO： After first treatment, there was no significant difference between low-dose treatment group and high-dose treatment group （P 〉 0.05）; but both groups were higher than control group, and there was significant difference （P 〈 0.05, 0.01）. CONCLUSION： NO vector of ultrasonic atomizing inhalation can improve VBI so as to improve cerebral blood-supply state.

a Transcranial Doppler Study of Locally Using Dexamethasone after Brain Injury in Rabbits

Objective To explore the effect of locally using dexamethasone on the blood flow velocity in the middle cerebral artery(FVmca) and cerebral edema after brain injury. Methods 20 rabbits were classified to 2 groups, group A( the control group) and B (the treated group). An experimental rabbit model was conducted to contusion by bone window plasty with extradural hitting. Group B was treated by locally infiltrating of dexamethasone at equidistance to lesions. Group A was given normal saline the same way as Group B. The changes of FVmca using trans－cranial Doppler and moisture in brain tissues were observed. Results The normal value of FVmca was (31.8± 4.5)cm/s, while the value of FVmca in group A and B were (15.4± 3.9)cm/s and (22.1± 3.5)cm/s separately.Water content in damaged hemisphere in Group A and B were (81.54± 0.55)％ and (79.35± 0.50)％ respectively. There was a significant difference between the 2 groups (P<0.05). The levels of FVmca in group A and B were lower than that of control and there was also a significant difference between group A and B (P<0.05).Conclusions FVmca decreased and the brain moisture increased after brain injury while FVmca increased and the brain moisture reduced after treatment with dexamethasone. It demonstreated that local treatment of dexamethasone had an obvious therapeutical effect on brain injury.

Evaluation of right-to-left shunt on contrast-enhanced transcranial Doppler in patent foramen ovale-related cryptogenic stroke: Research based on imaging

BACKGROUND Cardiogenic embolism caused by patent foramen ovale(PFO)is a common etiology of cryptogenic stroke(CS),particularly in young and middle-aged patients.Studies about right-to-left shunt(RLS)detection using contrast-enhanced transcranial Doppler(c-TCD)are numerous.According to the time phase and number of microbubbles detected on c-TCD,RLS can be classified and graded.We hypothesized that the characteristics of an infarction lesion on diffusion-weighted imaging differs when combining the type and grade of RLS on c-TCD in patients with PFO-related CS.AIM To explore the characteristics of infarction lesions on diffusion-weighted imaging when combining the RLS type and grade determined by c-TCD.METHODS We retrospectively evaluated CS patients from August 2015 to December 2019 at a tertiary hospital.In total,111 PFO-related CS patients were divided according to whether RLS was permanent(microbubbles detected both at resting state and after the Valsalva maneuver)or latent(microbubbles detected only after the Valsalva maneuver)on c-TCD.Each group was subdivided into small,mild and large RLS according to the grade of shunt on c-TCD.A normal control group was composed of 33 patients who suffered from simple dizziness.Intragroup and intergroup differences were analyzed in terms of clinical,laboratory and diffusion-weighted imaging lesion characteristics.The correlation between RLS grade evaluated by c-TCD and size of PFO determined by transesophageal echocardiography were also analyzed.RESULTS In 111 patients with PFO-related CS,68 had permanent RLS and 43 had latent RLS.Clinical characteristics and laboratory tests were not significantly different among the permanent RLS,latent RLS and normal control groups.The proportion of patients with multiple territory lesions in the permanent RLS group(50%)was larger than that in the latent RLS group(27.91%;P=0.021).Posterior circulation was more likely to be affected in the latent RLS group than in the permanent RLS group(30.23%vs 8.82%,P=0.004).Permanent-large and latent-large RLS were both more likely to be related to multiple(P_(trend)=0.017 and 0.009,respectively),small(P_(trend)=0.035 and 0.006,respectively)and cortical(P_(trend)=0.031 and 0.033,respectively)lesions.The grade of RLS evaluated by c-TCD was correlated to the size of PFO determined by transesophageal echocardiography(r=0.758,P<0.001).CONCLUSION Distribution of the infarct suggested the possible type of RLS.Multiple,small and cortical infarcts suggest large RLS induced by a large PFO.

Microembolic signal detection by transcranial Doppler: Old method with a new indication

Transcranial Doppler(TCD) is useful for investigation of intracranial arterial blood flow and can be used to detect a real-time embolic signal. Unfortunately, artefacts can mimic the embolic signal, complicating interpretation and necessitating expert-level opinion to distinguish the two. Resolving this situation is critical to achieve improved accuracy and utility of TCD for patients with disrupted intracranial arterial blood flow, such as stroke victims. A common type of stroke encountered in the clinic is cryptogenic stroke(or stroke with undetermined etiology), and patent foramen ovale(PFO) has been associated with the condition. An early clinical trial of PFO closure effect on secondary stroke prevention failed to demonstrate any benefit for the therapy, and research into the PFO therapy generally diminished. However, the recent publication of large randomized control trials with demonstrated benefit of PFO closure for recurrent stroke prevention has rekindled the interest in PFO in patients with cryptogenic stroke. To confirm that emboli across the PFO can reach the brain, TCD should be applied to detect the air embolic signal after injection of agitated saline bubbles at the antecubital vein. In addition, the automated embolic signal detection method should further facilitate use of TCD for air embolic signal detection after the agitated saline bubbles injection in patients with cryptogenic stroke and PFO.

Carotid Doppler and transcranial Doppler in diagnosing transient ischemic attack: A healthy control

BACKGROUND： If changes of hemodynamics in internal or external cranial artery and stenosis of atherosclerosis are found eady, patients with transient ischemic attack （TIA） may be treated at an eady phase so as to prevent and decrease the onset of cerebral infarction. Carotid Doppler can analyze carotid canal wall, hemodynamic properties and stenosis, and changes of plaque morphology; however, transcranial Doppler （TCD） can evaluate vascular stenosis and occlusion and judge collateral circulation in cranium through detecting velocity and direction of blood flow. Can the association of them increase the diagnostic rate of TIA？ OB3ECTIVE： To evaluate the effect of the association of carotid Doppler and TCD on TIA in internal carotid artery. DESIGN： Contrast observational study SETTING： Department of Neuroelectrophysiology, Central People＇s Hospital of Huizhou PARTICIPANTS： A total of 54 patients with TIA in internal carotid artery were selected from the Department of Neurology of Huizhou Central People＇s Hospital from May 2004 to June 2005. There were 35 males and 24 females aged 46-81 years. The clinical situation was asthenia of single limb, hemiplegia, anaesthesia of single upper or lower limb, hemianesthesia, sensory disorder and aphasia. The symptoms lasted for less than 2 hours. All cases were diagnosed with CT, and those who had pathological changes of acute cerebral infarction and history of cardiac disease were excluded. Additionally, 50 healthy subjects who were regarded as control group were selected from the Department of Neurology of Huizhou Central People＇s Hospital. There were 30 males and 20 females aged 45-80 years. All subjects were consent. METHODS： HD15000 color Doppler ultrasound （Philips Company, USA） and Muliti-DopX2 TCD （DWL Company, Germany） were used to detect hemodynamics, stenosis and distribution of atherosclerosis in carotid artery and internal carotid artery. Evaluation of marker： Stenosis was calculated by the ratio between the minimal cavity and vascular sectional area at the maximal site of plaque （mild： stenosis 〈 50%; moderate and severe： stenosis t〉 50%）. With TCD, the following results were regarded as stenosis： blood velocity of average envelope 〉 120 cm/s （diagnostic criteria of vascular stenosis of basilar artery： blood velocity of average envelope 〉 80 cm/s）, increase and segmental property of blood flow, and murmu of turbulent flow and vessel. MAIN OUTCOME MEASURES： Positive rate of atherosclerosis and incidence of stenosis with carotid Doppler and TCD. RESULTS： All 54 TIA patients and 50 healthy subjects were involved in the final analysis. ① Results of carotid Doppler： Atherosclerosis and stenosis were obvious in experimental group. Positive rate of atherosclerosis was 85% （46/54） and incidence of stenosis of carotid artery was 41% （22/54）, which were higher than those in control group [52% （26/54）, 41% （22/54）, x^2 = 13.42, 10.90, P 〈 0.01]. ② Results of TCD： In experimental group, positive rate of atherosclerosis at base of skull was 89% （48/54） and incidence of stenosis of internal cranial artery was 48% （26/54）, which were higher than those in control group [62% （31/50）, 0, x^2 = 10.28, 32.00, P 〈 0.01]. Stenosis of artery was mainly involved in middle cerebral artery, initial segment and crotch of carotid artery. CONCLUSION： The association of carotid Doppler and TCD can increase clinically diagnostic rate of TIA and provide bases for apposition and intensity of TIA lesion.

Comparison of detection results of hypoxic-ischemic encephalopathy at different degrees in infant patients between brain electrical activity mapping, transcranial Doppler sonography and computer tomography examinations

BACKGROUND： It has been proved that brain electrical activity mapping （BEAM） and transcranial Doppler （TCD） detection can reflect the function of brain cell and its diseased degree of infant patients with moderate to severe hypoxic-ischemic encephalopathy （HIE）. OBJECTIVE： To observe the abnormal results of HIE at different degrees detected with BEAM and TCD in infant patients, and compare the detection results at the same time point between BEAM, TCD and computer tomography （CT） examinations. DESIGN ： Contrast observation SETTING： Departments of Neuro-electrophysiology and Pediatrics, Second Affiliated Hospital of Qiqihar Medical College. PARTICIPANTS： Totally 416 infant patients with HIE who received treatment in the Department of Newborn Infants, Second Affiliated Hospital of Qiqihar Medical College during January 2001 and December 2005. The infant patients, 278 male and 138 female, were at embryonic 37 to 42 weeks and weighing 2.0 to 4.1 kg, and they were diagnosed with CT and met the diagnostic criteria of HIE of newborn infants compiled by Department of Neonatology, Pediatric Academy, Chinese Medical Association. According to diagnostic criteria, 130 patients were mild abnormal, 196 moderate abnormal and 90 severe abnormal. The relatives of all the infant patients were informed of the experiment. METHOOS： BEAM and TCD examinations were performed in the involved 416 infant patients with HIE at different degrees with DYD2000 16-channel BEAM instrument and EME-2000 ultrasonograph before preliminary diagnosis treatment （within 1 month after birth） and 1,3,6,12 and 24 months after birth, and detected results were compared between BEAM, TCD and CT examinations. MAIN OUTCOME MEASURES： Comparison of detection results of HIE at different time points in infant patients between BEAM. TCD and CT examinations. RESULTS： All the 416 infant patients with HIE participated in the result analysis. （1） Comparison of the detected results in infant patients with mild HIE at different time points after birth between BEAM, TCD and CT examinations： BEAM examination showed that the recovery was delayed, and the abnormal rate of BEAM examination was significantly higher than that of CT examination 1 and 3 months after birth [55.4%（72/130）vs. 17.0% （22/130 ）,x^2=41.66 ;29.2% （ 38/130 ） vs. 6.2% （ 8/130 ）, x^2=23.77, P 〈 0.01 ], exceptional patients had mild abnormality and reached the normal level in about 6 months. TCD examination showed that the disease condition significantly improved and infant patients with HIE basically recovered 1 or 2 months after birth, while CT examination showed that infant patients recovered 3 or 4 months after birth. （2） Comparison of detection results of infant patients with moderate HIE at different time points between BEAM, TCD and CT examinations： The abnormal rate of BEAM examination was significantly higher than that of CT examination 1,3,6 and 12 months after birth [90.8% （178/196）,78.6% （154/196）,x^2=4.32,P 〈 0.05;64.3% （126/196）,43.9% （86/196） ,x^2=16.44 ;44.9% （88/196） ,22.4% （44/196）,x^2=22.11 ;21.4% （42/196）, 10.2% （20/196）,x^2=9.27, P 〈 0.01]. BEAM examination showed that there was still one patient who did not completely recovered in the 24^th month due to the relatives of infant patients did not combine the treatment,. TCD examination showed that the abnormal rate was 23.1%（30/196）in the 1^st month after birth, and all the patients recovered to the normal in the 3^rd month after birth, while CT examination showed that mild abnormality still existed in the 24^th month after birth （1.0% ,2/196）. （3） Comparison of detection results of infant patients with severe HIE at different time points between BEAM, TCD and CT examinations： The abnormal rate of BEAM examination was significantly higher than that of CT examination in the 1^st, 3^rd, 6^th and 12^th months after birth[86.7% （78/90）,44.4% （40/90）,x^2=35.53;62.2% （56/90）,31.1% （28/90）,x^2=17.51 ;37.8% （34/90）,6.7% （6/90）, x^2=27.14, P 〈 0.01]. BEAM examination showed that mild abnormality still existed in 4 infant patients in the 24^th month after birth. TCD examination showed that the abnormal rate was 11.1% （10/90） in the 3^rd month after birth, and all the infant patients recovered in the 6^th month after birth. CT examination showed that the abnormal rate was 6.7%（6/90） in the 12^th month after birth, and all of infant patients recovered to the normal in the 24^th month after birth.CONCLUSION ： BEAM is the direct index to detect brain function of infant patients with HIE, and positive reaction is still very sensitive in the tracking detection of convalescent period. The positive rate of morphological reaction in CT examination is superior to that in TCD examination, and the positive rate is very high in the acute period of HIE in examination.

Evaluation of Early Acute Cerebral Infarction with Transcranial Doppler

Objective:For patients with early acute cerebral infarction(ACI),transcranial Doppler ultrasound was used in the clinical examination,and its application effect was observed and analyzed.Methods:This study was carried out between October 2018 and October 2019.50 patients with ACI included as the research object was evaluated by transcranial Doppler and CT examination,and the application of the two examination methods was compared.Results:The results of transcranial Doppler examination showed that the abnormal rate of blood flow velocity and the ratio of both sides(VACA)in patients with early ACI was higher than that of CT examination.Conclusion:With the impact on the location and area of vascular occlusion in patients,VACA can effectively reflect the status and effectiveness of the collateral circulation function of the patient’s pia vessels during cerebral infarction.

TRANSCRANIAL DOPPLER CHARACTERISTICS IN PERSISTENT VEGETATIVE STATUS,LOCKED-IN SYNDROME AND BRAIN DEATH

Persistentvegetativestatus(PVS),lockedinsyndromeandbraindeathpatientsareusuallyconfusedintheclinic.TrascranialDopplerisabletodistinguishthisthreestatusaccordingtothedifferentcerebralbloodflow.ThispaperreportstheresultsoftranscranialDopplerultrasounde...

Monitoring of antegrade selective cerebral perfusion for aortic arch surgery with transcranial Doppler ultrasonography and near-infrared spectroscopy

目的 为评估经右锁骨下动脉插管进行选择性顺行脑灌注 (ASCP)的有效性和安全性 ,作为扩展主动脉外科全身停循环的安全期限的一种手段 ,用多单位神经监测来客观地量化其生理反应。方法 择期主动脉外科病人 2 2例 ,所有病人年龄均小于 6 0岁。术前用经颅多谱勒 (TCD)确证颈动脉和锥基底动脉系统通畅和存在有效的侧枝灌注。通过右锁骨下动脉插管建立体外循环。用TCD测量大脑中动脉的峰血流速度 ,反映ASCP的幅度。同时 ,用双波长近红外线光谱仪持续监测局部脑氧饱和度 (rSO2 )。结果 所有病人恢复顺利。当ASCP流量 <5ml·kg 1·min 1时 ,则监测不到大脑中动脉血流 ,调节最低流量在 15- 2 0ml·kg 1·min 1时 ,则维持rSO2 >50 %。ASCP流量与大脑中动脉的峰血流速度和rSO2 均呈高度相关性 (r =0 86和 0 96 ,P <0 0 1)。结论 神经监测下进行ASCP可能扩展主动脉外科全身停循环的安全期限 。

Outcome prediction in severe traumatic brain injury with transcranial Doppler ultrasonography

Objective: To investigate the value of transcranial Doppler (TCD) ultrasonography in evaluating the outcome of severe traumatic brain injury and to correlate the TCD values with intracranial pressure (ICP) and cerebral perfusion pressure (CPP) monitoring. Methods: A prospective study was conducted to evaluate the contribution of TCD ultrasonography to neurological outcome in a series of 96 severe traumatic brain injury patients. The quantitative variables of TCD ultrasonography included the mean blood flow velocity of the middle cerebral artery (MCA) and pulsatility index within the first 24 hours of admission. The ICP and CPP values were also recorded. Outcome in 6 months postinjury was evaluated using the Glasgow Outcome Scale (GOS 4 5 was considered as "good" and GOS 1 3 as "poor"). Results: The mean blood flow velocity of the MCA was larger than 40 cm/s in 30 (51%) patients with good outcome whereas it was less than 40 cm/s in 27 (73%) patients with poor outcome (P< 0.025 ). The mean PI in cases of good outcome (34 patients, 57%) was lower than 1.5 whereas in poor outcome (30 patients, 83%) was higher than 1.5 (P< 0.001 ). The correlations of ICP and CPP to pulsatility index were statistically significant (P< 0.01 ). Conclusions: TCD ultrasonography is valid in predicting the patients outcome of 6 months and correlates significantly with ICP and CPP values when it is performed in the first 24 hours of severe traumatic brain injury.

Point-of-care ultrasonography spotlight:Could venous excess ultrasound serve as a shared language for internists and intensivists?

Point-of-care ultrasonography(POCUS),particularly venous excess ultrasound(VExUS)is emerging as a valuable bedside tool to gain real-time hemodynamic insights.This modality,derived from hepatic vein,portal vein,and intrarenal vessel Doppler patterns,offers a scoring system for dynamic venous congestion assessment.Such an assessment can be crucial in effective management of patients with heart failure exacerbation.It facilitates diagnosis,quantification of congestion,prognostication,and monitoring the efficacy of decongestive therapy.As such,it can effectively help to manage cardiorenal syndromes in various clinical settings.Extended or eVExUS explores additional veins,potentially broadening its applications.While VExUS demonstrates promising outcomes,challenges persist,particularly in cases involving renal and liver parenchymal disease,arrhythmias,and situations of pressure and volume overload overlap.Proficiency in utilizing spectral Doppler is pivotal for clinicians to effectively employ this tool.Hence,the integration of POCUS,especially advanced applications like VExUS,into routine clinical practice necessitates enhanced training across medical specialties.

Clinical utilization of microembolus detection by transcranial Doppler sonography in intracranial stenosis-occlusive disease

Objective To discuss the clinical ultiliazation and significance of microembolus detection by transcranial Doppler （TCD） sonography in intracranial stenosis-occlusive disease. Data sources All related articles in this review were mainly searched from PubMed published in English from 1996 to 2012 using the terms of microembolic signal, transcranial Doppler, intracranial stenosis, stroke. Study selection Original articles and reviews were selected if they were related to the clinical utilization of microembolus detection in intracranial stenosis-occlusive disease. Results Intracranial stenosis is a significant cause of cerebral emboli, and microembolus detection by TCD sonography were widely used in exploring the mechanisms of ischemic stroke with intracranial stenosis （including the middle cerebral artery stenosis and the vertebral-basilar stenosis）, evaluating the prognosis of acute stroke, evaluating the therapeutic effects, and predicting the recurrent events of stroke. Conclusion Microembolus detection by TCD sonography plays an important role in the cerebral ischemic stroke patients with intracranial stenosis.

Compromised cerebrovascular modulation in chronic anxiety:evidence from cerebral blood flow velocity measured by transcranial Doppler sonography

Objective Cerebral autoregulation （CA） is the mechanism by which constant cerebral blood flow is maintained despite changes in cerebral perfusion pressure. CA can be evaluated by dynamic monitoring of cerebral blood flow velocity （CBFV） with transcranial Doppler sonography （TCD）. The present study aimed to explore CA in chronic anxiety. Methods Subjects with Hamilton anxiety scale scores 〉14 were enrolled and the dynamic changes of CBFV in response to an orthostatic challenge were investigated using TCD. Results In both the anxious and the healthy subjects, the mean CBFV was significantly lower in the upright position than when supine. However, the CBFV changes from supine to upright differed between the anxious and the healthy groups. Anxious subjects showed more pronounced decreases in CBFV with abrupt standing. Conclusion Our results indicate that cerebrovascular modulation is compromised in chronic anxiety; anxious subjects have some insufficiency in maintaining cerebral perfusion after postural change. Given the fact that anxiety and impaired CA are associated with cardiovascular disease, early ascertainment of compromised cerebrovascular modulation using TCD might suggest interventional therapies in the anxious population, and improve the primary prevention of cardiovascular disease.

Transcranial Doppler for detection of changes in ophthalmic artery blood flow

The ophthalmic artery （OA） is a main branch of the internal carotid artery （ICA）. Severe internal carotidartery stenosis or occlusion may not only affect the blood supply to the brain, but may also cause OA insufficiency, leading to ocular ischemia. Therefore, research on the hemodynamic changes in the OA in patients with ICA stenosis or occlusion has increasingly attracted more ophthalmologists＇ attention.1 Transcranial Doppler （TCD） is simple and noninvasive, has been widely used in the inspection of cerebrovascular disease,

The value of color Doppler ultrasonography in monitoring normal orthotopic liver transplantation and postoperative complications

OBJECTIVE: To assess the value of color Doppler ultrasonography in monitoring normal orthotopic liver transplantation and postoperative complications. METHODS: Forty-one patients after orthotopic liver transplantation were examined by using color Doppler flow imaging to observe the hepatic blood flow and change of ultrasonography of the hepatic parenchyma and bile duct. The measured indexes included maximum blood flow velocity, time-average blood flow velocity (TAV), resistance index (RI) and diameter of the bile duct. RESULTS: Among 41 patients, 17 (41.5%) suffered from liver transplant rejection. Of the 17 patients, 13 (76.4%) showed decrease of TAV of the portal vein, 15 (88.25%) low-amplitude single-phase serrated wave or negative biphasic wave of the hepatic vein, 9 (52.9%) increased hepatic arterial RI, and 5 (29.4%) slightly dilated bile duct. Sonography showed disappearance of the hepatic artery blood flow around the portal vein in 5 (12.2%) of the 41 patients with hepatic artery thrombosis in the postoperative period. Slight dilatation of the intrahepatic bile duct was found in 3 (7.3%) of the 41 patients in the early postoperational period and it normalized within 2 weeks. Ultrasonography of 20 patients (48.8%) revealed a visible dilatation of the intrahepatic bile duct, which was worsening gradually. The causes of bile duct dilatation included biliary stricture in 2 patients (10%), stone in 15 patients (75%) and others in 3 patients (15%). CONCLUSIONS: Color Doppler ultrasonography is valuable for monitoring normal liver transplantation and postoperative complications.

Different hemodynamic responses by color Doppler ultrasonography studies between sildenafil non-responders and responders

Aim： To determine if there are different penile hemodynamic patterns between sildenafil non-responders and responders by using color Doppler ultrasonography. Methods： A total of 69 erectile dysfunction （ED） patients aged 22-79 years were enrolled into the present study. Thirty-eight （55.1%） men with ED who did not respond to four attempts of treatment with 100 mg sildenafil after re-education were classified as sildenafil non-responders. A com- bination of three vasodilator drugs, 1.25 mg papaverine, 0.4 mg phentolamine and 5 ug prostaglandin E1, was given by intracavernous injection before penile Doppler ultrasonography was carried out. The erectile response to intracavernous injection and vascular parameters including peak systolic velocity （PSV）, resistance index （RI）, end diastolic velocity （EDV） and cavernosa artery diameter （CD） were measured and the results between sildenafil nonresponders and responders were compared. Results： No statistical difference in vascular parameters measured by Doppler ultrasonography studies between non-responders and responders was noted. Sildenafil non-responders had a poorer penile rigidity response to intracavernous injection than responders （P 〈 0.05）. Among patients with adequate PSV （〉 30 cm/s） and abnormal EDV （〉 5 cm/s）, individuals in the non-responder group had fewer positive responses to intracavernous vasodilator injection than in the responder group （35.3% vs. 72.2%, P 〈 0.05）. Advanced age and comorbidity with diabetes mellitus were significantly associated with sildenafil non-response （P 〈 0.05）. Conclusion： Sildenafil non-responders were characterized by a poorer penile rigidity response to intracavernous injection and had an associated impaired veno-occlusive mechanism. Advanced age and comorbidity with diabetes mellitus were two common factors associated with non-response.

Postoperative complications in patients with portal vein thrombosis after liver transplantation:Evaluation with Doppler ultrasonography

AIM: To study the postoperative complications in patients with preoperative portal vein thrombosis (PVT) undergoing liver transplantation (LT) and to evaluate the complications with Doppler ultrasonography. METHODS: Retrospective studies were performed on 284 patients undergoing LT (286 LT) with respect to pre-and postoperative clinical data and Doppler ultrasonography. According to the presence and grade of preoperative PVT, 286 LTs were divided into three groups: complete PVT (c-PVT), partial PVT (p-PVT) and non-PVT, with 22, 30 and 234 LTs, respectively. Analyses were carried out to compare the incidence of early postoperative complications. RESULTS: PVT, inferior vena cava (IVC) thrombosis, hepatic artery thrombosis (HAT) and biliary complications were found postoperatively. All complications were detected by routine Doppler ultrasonography and diagnoses made by ultrasound were confirmed by clinical data or/and other imaging studies. Nine out of 286 LTs had postoperative PVT. The incidence of the c-PVT group was 22.7%, which was higher than that of the p-PVT group (3.3%, P < 0.05) and non-PVT group (1.3%, P < 0.005). No difference was found between the p-PVT and non-PVT groups (P > 0.25). Of the 9 cases with postoperative PVT, recanalizations were achieved in 7 cases after anticoagulation under the guidance of ultrasound, 1 case received portal vein thrombectomy and 1 case died of acute injection. Ten LTs had postoperative IVC thrombosis. The c-PVT group had a higher incidence of IVC thrombosis than the non-PVT group (9.1% vs 2.6%, P < 0.05); no significant difference was found between either the c-PVT and p-PVT groups (9.1% vs 6.7%, P > 0.5) or between the p-PVT and non-PVT groups (P > 0.25). Nine cases with IVC thrombosis were cured by anticoagulation under the guidance of ultrasound, and 1 case gained natural cure without any medical treatment after 2 mo. HAT was found in 2 non-PVT cases, giving a rate of 0.7% among 286 LTs. Biliary complications were seen in 12 LTs. The incidence of biliary complications in the c-PVT, p-PVT and non-PVT groups was 9.1%, 3.3% and 4.3%, respectively (P > 0.25 for all), among which 2 stenosis led retransplantations and others were controlled by relative therapy. CONCLUSION: C-PVT patients tend to have a higher incidence of PVT and IVC thrombosis than non-PVT patients after LT. The incidence of postoperative complications in p-PVT patients does not differ from that of non-PVT patients. A relatively low incidence of HAT was seen in our study. Doppler ultrasonography is a convenient and efficient method for detecting posttransplant complications and plays an important role in guiding treatment.

Use of color Doppler ultrasonography in the diagnosis of anomalous connection in pancreatobiliary disease

AIM: To estimate the detectability of anomalous connection in pancreatobiliary disease (ACPBD) cases, measuring gallbladder wall blood flow (GWBF).METHODS: In the retrospective study, we enrolled 42subjects with gallbladder wall thickening. GWBF velocity was determined as an average value of the peak velocity of color signals on the gallbladder wall, three times in each case. Based on the findings on endoscopic ultrasonography (EUS) or endoscopic retrograde cholangiopancreatography (ERCP), the 42 subjects were divided into 11 cases with ACPBD and 31 cases without ACPBD. In the prospective study, the subjects were 92 cases with gallbladder wall thickening. Using the cut-off level of the flow velocity obtained in the retrospective study, the usefulness of measuring GWBF velocity in diagnosing ACPBD was evaluated.RESULTS: In the retrospective study, imaging of GWBF was obtained in 40 of the 42 subjects. The mean GWBF velocity of the ACPBD cases was 29.4±3.9 cm/s(mean±SD), which was significantly different (P＜0.0001;95% CI 5.48-13.2) from that of the without ACPBD cases(20.1±5.9 cm/s). Based on this result, we prepared a receiver operating characteristic curve, and the cut-off level appropriate for diagnosing ACPBD was estimated to be 25 cm/s. In the prospective study, GWBF was detected in 86 of the 92 subjects. Based on the EUS or ERCP findings, the 92 subjects were divided into 15 cases with ACPBD and 77 cases without ACPBD. When a cut-off level of 25 cm/s was employed, ACPBD could be diagnosed with a sensitivity of 87.0% (13/15) and a specificity of87.3% (62/71).CONCLUSION: Measurement of GWBF velocity, which is less invasive and provides objective values, is very useful for diagnosing ACPBD prior to the development of malignant tumors in cases with gallbladder wall thickening.