PURPOSE: The arterial pulsatility index (PI) is measured by transcranial Doppler ultrasonography (TCD) and is postulated to reflect the vascular resistance distal to the artery being examined. An increased PI of the intracranial artery is often reported with diabetes mellitus (DM), old age, hypertension, intracranial hypertension, vascular dementia, and small artery disease. Microvascular complication of DM, which may contribute to cerebral infarction, involves the small perforating artery and may influence the PI of the proximal artery. MATERIALS AND METHODS: We performed a TCD examination in patients with type 2 DM with acute lacunar infarction (DML, n=35), type 2 DM without cerebral infarction (DMO, n=69), and in control cases with no DM or cerebral infarction (control group, n=41). We then compared the TCD findings among these groups. RESULTS: The PI was significantly higher in the DML and DMO groups than in the control group (1.05, 0.93, 0.73. respectively, for the right middle cerebral artery; 1.04, 0.90, 0.73, respectively, for the left middle cerebral artery; 0.97, 0.89, 0.70, respectively, for the basilar artery). The PI was also significantly higher in the DML group than in the DMO group for both middle cerebral arteries. The flow velocity was comparable among the three groups. CONCLUSION: The elevated PI of the intracranial arteries may reflect diabetic cerebral microvascular complications. The PI measurement using TCD may be a useful predictor of lacunar infarction in type 2 DM patients.
Aged ; Basilar Artery/physiology/ultrasonography ; Brain/*blood supply ; Brain Infarction/complications/*ultrasonography ; Diabetes Mellitus, Type 2/*complications ; Diabetic Angiopathies/*ultrasonography ; Female ; Humans ; Male ; Middle Aged ; Middle Cerebral Artery/physiology/ultrasonography ; Pulsatile Flow ; Retrospective Studies ; Ultrasonography, Doppler, Transcranial

OBJECTIVETo explore the pattern of variations in middle cerebral artery peak systolic velocity (MCA PSV) and cardiothoracic ratio (CTR) during early pregnancy, establish their reference ranges and explore their correlation with the crown-rump length (CRL).

METHODSA total of 522 pregnant women with normal findings in antenatal examinations underwent routine color Doppler ultrasound examination to collect the data of MCA PSV, CTR and CRL. The reference ranges of MCA PSV and CTR for different CRL levels were established, and the correlation of MCA PSV and CTR with CRL was analyzed.

RESULTSDuring the first trimester, MCA PSV and CRL showed a moderate positive correlation with a correlation coefficient of 0.426 (P<0.001), while CTR and CRL showed no significant correlation (0.168, P<0.001). The reference range of MCA PSV was 14.35 (14.08-14.62) cm/s and that of CTR was 0.34 (0.33-0.34) during early pregnancy.

CONCLUSIONColor Doppler ultrasound is a safe and feasible modality to assess fetal MCA PSV and CTR for detecting fetal growth abnormalities in early pregnancy. The established reference ranges of MCA PSV and CTR offer a clinical theoretical basis for detecting α-thalassemia in early pregnancy.

Blood Flow Velocity ; Crown-Rump Length ; Female ; Fetal Diseases ; diagnostic imaging ; Humans ; Middle Cerebral Artery ; physiology ; Pregnancy ; Pregnancy Trimester, First ; Reference Values ; Systole ; Ultrasonography, Doppler, Color ; Ultrasonography, Prenatal

PURPOSE: Lacunar stroke, in the context of small vessel disease, is a type of cerebral infarction caused by occlusion of a penetrating artery. Pulsatility index (PI) is an easily measurable parameter in Transcranial Doppler ultrasound (TCD) study. PI reflects distal cerebral vascular resistance and has been interpreted as a surrogate marker of small vessel disease. We hypothesized that an increased PI, a marker of small vessel disease, might be associated with a larger infarct volume in acute lacunar stroke. MATERIALS AND METHODS: This study included 64 patients with acute lacunar stroke who underwent TCD and brain MRI. We evaluated the association between the mean PI value of bilateral middle cerebral arteries and infarct volume on diffusion-weighted MRI using univariate and multivariate linear regression. RESULTS: The mean infarct volume and PI were 482.18±406.40 mm3 and 0.86±0.18, respectively. On univariate linear regression, there was a significant positive association between PI and infarct volume (p=0.001). In the multivariate model, a single standard deviation increase of PI (per 0.18) was associated with an increase of 139.05 mm3 in infarct volume (95% confidence interval, 21.25 to 256.85; p=0.022). CONCLUSION: We demonstrated that PI was an independent determinant of infarct volume in acute lacunar stroke. The PI value measured in acute stroke may be a surrogate marker of the extent of ischemic injury.
Aged ; Cerebral Infarction/*diagnostic imaging/*physiopathology ; *Diffusion Magnetic Resonance Imaging ; Female ; Humans ; Linear Models ; Male ; Middle Aged ; Middle Cerebral Artery ; Pulsatile Flow/physiology ; Retrospective Studies ; Stroke, Lacunar/*diagnostic imaging/*physiopathology ; *Ultrasonography, Doppler, Transcranial ; Vascular Resistance/physiology

The changes of arterial carbon dioxide partial pressure considerably influence cerebral blood flow and different anesthetic agents have different effects on cerebrovascular physiology. However the importance of these differences in neuroanesthetic practice are unclear. Transcranial Doppler ultrasonography allows the noninvasive direct measurements of cerebral blood flow velocity and direction in the basal brain arteries. The authors performed transcranial Doppler ultrasonography to measure the blood flow velocity of middle cerebral artery in 12 patients who were anesthetized with 10 mcg/kg of fentanyl and 66 % nitrous oxide in oxygen(fentanyl group) and 12 patients with 1.0 vo1% isoflurane and 66 % nitrous oxide in oxygen(isoflurane group) during normocapnia(P(ET)CO(2)=38 mmHg) and hypocapnia(P(ET)CO(2)=28 mmHg)state. The carbon dioxide reactivity was expressed as the changes in mean blood flow velocity per unit changes in endtidal carbon dioxide partial pressure(P(ET)CO(2)). Mean blood flow velocity of middle cerebral artery decreased from 46.6+/-8.9 cm/s to 30.0+/-5.3 cm/s in the fentanyl group and 42.7+/-5.6 cm/s to 32.5+/-4.6 cm/s in the isoflurane group as the P(ET)CO(2) decreased from 38 mmHg to 28 mmHg. There was a significant difference between the CO2 reactivity of fentanyl group(1.7+/-0.7 cm/s/mmHg) and isoflurane group(1,0+/-0,2 cm/s/mmHg) (p<0.05). It is concluded that hyperventilation is more likely to affect cerebral blood flow during fentanyl-nitrous oxide anesthesia than during isoflurane-nitrous oxide anesthesia.
Anesthesia ; Anesthetics ; Arteries ; Blood Flow Velocity ; Brain ; Carbon Dioxide ; Fentanyl* ; Humans ; Hyperventilation ; Isoflurane* ; Middle Cerebral Artery ; Nitrous Oxide ; Partial Pressure ; Physiology ; Ultrasonography, Doppler, Transcranial

OBJECTIVE: To investigate the diagnostic value of transcranial Doppler ultrasound in early stage cerebral arteriosclerosis. METHODS: We selected 50 patients with early cerebral arteriosclerosis as the disease group. At the same time we selected another 50 patients as a control group with no significant symptoms in the nervous system. By 2 MHz pulse Doppler probe through double-temporal windows and pillow windows Basilar artery (BA), the bilateral middle cerebral artery (MCA) was detected. In the TCD spectrum, we selected the spectrum of a single-family cardiac cycle, identified the starting point (ts), pulse-incisure point (ti), end point (te), and the peak velocity (tp), measured the time of the spectrum starting point to the peak velocity (Tp) and calculated the time required for the peak velocity in the share of ventricular systolic (Tp/Ti), the time required for the peak velocity in the share of the whole cardiac cycle (Tp/T). Tp, Tp/Ti and Tp/T were respectively named as time to peak velocity (TPV), peak-time index-1 (PTI-1) and peak-time index-2 (PTI-2). All data were analyzed by SPSS13.0. RESULTS: There was no significant difference in blood vessel velocity, PI, RI and S/D of BA and RMCA (P>0.05) between the control group and the disease group. Compared with the control group, TPV of the BA, LMCA and RMCA significantly extended, PTI-1 and PTI-2 of BA, LMCA and RMCA increased significantly in the disease group (P<0.01). In the disease group, there was no significant correlation between peak time index and PI, S/D (P>0.05). CONCLUSION TPV, PTI-1 and PTI-2 are sensitive indicators of early stage cerebral arteriosclerosis.
Adult ; Basilar Artery ; diagnostic imaging ; Blood Flow Velocity ; physiology ; Case-Control Studies ; Female ; Humans ; Intracranial Arteriosclerosis ; diagnostic imaging ; Male ; Middle Aged ; Middle Cerebral Artery ; diagnostic imaging ; Ultrasonography, Doppler, Transcranial