Comparison between laser speckle contrast imaging and laser Doppler imaging to assess skin blood flow in humans

Objective

We tested the linearity between skin blood flux recorded with laser speckle contrast imaging (LSCI) and laser Doppler imaging (LDI), comparing different ways of expressing data. A secondary objective was to test within-subject variability of baseline flux with the two techniques.

Methods

We performed local heating at 36, 39, 42, and 44 °C on the forearm of healthy volunteers, and measured cutaneous blood flux with LDI and LSCI. Biological zero (BZ) was obtained by occluding the brachial artery. We expressed data as raw arbitrary perfusion units (APUs) and as a percentage increase from baseline (%BL), with and without subtracting BZ. Inter-site variability was expressed as a within subject coefficient of variation (CV).

Results

Twelve participants were enrolled. Inter-site variability at baseline was lower with LSCI (CV = 9.2%) than with LDI (CV = 20.7%). We observed an excellent correlation between both techniques when data were expressed as raw APUs or APU − BZ (R = 0.90; p < 0.001). The correlation remained correct for %BL (R = 0.77, p < 0.001), but decreased for %BL − BZ (R = 0.44, p = 0.003). Bland-Altman plots revealed a major proportional bias between the two techniques.

Conclusion

This study suggests that skin blood flux measured with LSCI is linearly related to the LDI signal over a wide range of perfusion. Subtracting BZ does not affect this linearity but introduces variability in baseline flux, thus decreasing the correlation when data are expressed as a function of baseline. Finally, systematic bias makes it impossible to assimilate arbitrary perfusion units provided by the two systems.     

Alterations in thyroid blood flow induced by varying levels of iodine intake in the rat

Thyroid hormone biosynthesis depends upon the presence of adequate amounts of thyroidal iodine, and during fluctuations in dietary iodine intake, relatively constant thyroid hormone levels are maintained by various homeostatic mechanisms. These mechanisms include an enhancement of iodide pump efficiency and organification when iodine intake is limited, and significant decreases in iodide uptake and hormone synthesis when excess iodine intake occurs. The present study was designed to determine whether acclimation to different dietary iodine regimens is associated with changes in thyroid blood flow and to assess the time course of any such alterations in relation to pituitary-thyroid axis hormone levels. Male Sprague-Dawley rats were fed a diet containing low (LID), high (HID), or normal (CTR) iodine concentrations. Three, 7, 14, or 133 days after starting these dietary regimens, the animals were anesthetized with ketamine/pentobarbital, and thyroid blood flows were assessed using the reference sample version of the microsphere technique. At the same times and at weekly intervals throughout the 133 days of treatment, blood samples for the determination of TSH, T4, and T3 levels were obtained. Additionally, thyroidal immunoreactive vasoactive intestinal peptide (VIP) was measured at the end of the experiments. LID treatment increased thyroid blood flows to 240%, 350%, and 240% of levels in control rats at 7, 14, and 133 days of treatment, respectively. Thyroid weight was also elevated above levels in control animals at each of these times. A slight decrease in plasma T4 levels occurred over the 133 days of LID treatment; however, this dietary regimen did not alter circulating levels of T3 or TSH or thyroidal VIP concentration. HID treatment had opposite effects, in general, to those of LID. Thyroid blood flows were decreased by 34%, 56%, 46%, and 35% after 3, 7, 14, and 133 days of treatment with HID, respectively. Circulating levels of T4 were increased over the 133 days of HID treatment, whereas plasma levels of T3 and TSH and thyroid weights remained unchanged from those in control rats over this period of study. A small decrease in thyroidal VIP concentrations coincident with the decrease in thyroid blood flow was observed at the beginning of the HID treatment. Neither LID nor HID had any effect on blood pressure, cardiac output, or blood flow in other organs. These data demonstrate that acclimation to changes in dietary iodine intake in the rat include alterations in thyroid blood flow which are reciprocal to the iodine intake level and appear to be independent of circulating TSH levels.     

应用彩色多普勒超声检测脑血流灌注评价血管性痴呆

目的:探讨采用彩色多普勒超声检测颈内动脉及椎动脉血流估测脑血流灌注在评价血管性痴呆(VD)中的价值。方法:VD患者56例,对照组42例,采用GE Vivid 7彩色多普勒超声诊断仪,检测颈内动脉和椎动脉颅外段的血管内径、收缩期最大峰值流速(Vm)及流速-时间积分(VTI)以计算颈内动脉及椎动脉的每分血流量,2者相加获得总的血流量。结果:VD组双侧颈内动脉和椎动脉的Vm、颈内动脉血流量和总血流量均较对照组下降(P<0.05)。MMSE评分与总血流量呈正相关。结论:通过彩色多普勒超声对颈内动脉、椎动脉血流量指标进行检测,可较准确反映血管性痴呆患者脑血流灌注的改变,是一种研究血管性痴呆的有效方法和手段。     

Relationship between thyroid function and elevated blood pressure in euthyroid adults

Thyroid hormones (THs) have profound effects on cardiovascular functions, suggesting that THs may contribute to the development of elevated blood pressure (BP). Few studies, however, have systematically assessed the relationship between THs and elevated BP. We therefore conducted a cross‐sectional study to examine how serum THs concentrations are related to the prevalence of elevated BP in a euthyroid population. This study (n = 12 487) was performed in Tianjin, China. Serum free triiodothyronine (FT3), free thyroxine (FT4), and thyroid‐stimulating hormone (TSH) levels were measured by chemiluminescence immunoassay. Elevated BP was defined according to the JNC 8 criteria. Analysis of covariance and multiple logistic regression models were used to assess the relationships between FT3, FT4, and TSH quartiles and elevated BP. The multivariable‐adjusted odds ratios (95% confidence interval) of elevated BP for gradual increase in the FT3, FT4, and TSH quartiles, when compared to the lowest quartiles were 1.08 (0.97, 1.21), 1.24 (1.12, 1.39), and 1.32 (1.18, 1.47); 1.18 (1.06, 1.32), 1.18 (1.06, 1.31), and 1.24 (1.11, 1.38); 1.06 (0.96, 1.19), 1.06 (0.95, 1.18), and 1.03 (0.93, 1.15), respectively. Our study demonstrated that FT3 and FT4 are positively related to the prevalence of elevated BP in euthyroid adults, but no significant relationship was found between TSH and elevated BP.     

Visualization of coronary blood flow by color Doppler imaging with a transesophageal approach

To examine whether CBF can be imaged by color Doppler technique, we visualized CBF using a transesophageal color Doppler imaging system. In 36 of 39 patients with normal coronary arteriograms after heart surgery, the LMT and the proximal LAD were clearly imaged by 2-dimensional echocardiography. Among them, CBF was coded mainly in blue in 32 patients, showing that the flow runs from proximal to distal. In some cases, yellowish and/or reddish components were seen, suggesting the occurrence of aliasing associated with augmentation of flow velocity or flow turbulence. The fast Fourier transformation spectrogram of the pulsed Doppler sampled in the colored flow showed a typical flow velocity pattern of the LAD, which mainly consisted of a predominantly diastolic component. These results indicate that the transesophageal color Doppler technique is advantageous in noninvasively imaging CBF. It should be further sought whether flow abnormality due to coronary stenosis could be determined by this technique.     

功能性消化不良患者胃窦幽门十二指肠运动功能的研究

目的探讨胃窦幽门十二指肠运动功能在功能性消化不良（ＦＤ）发病中的作用。方法采用彩色多普勒超声技术对胃的蠕动周期、排空周期、胃窦幽门十二指肠协调收缩及幽门功能进行了研究。结果１４名正常人餐后胃收缩频率平均为３．１５±０．０２次／分，２１例ＦＤ病人为３．１８±０．０２次／分（Ｐ值＞０．０５）。正常人及ＦＤ病人餐后各时间段平均胃排空时间无明显差异。正常组＞１０秒的胃排空周期百分率为５３．３％，ＦＤ组为３２．４％（Ｐ值＜０．０１）。餐后胃窦幽门十二指肠协调收缩百分率为７１．０％，ＦＤ组为５８．３％（Ｐ值＜０．００１）。２１例病人中有５例表现有幽门关闭不全，占２３．８％。１４例正常人中无一例出现幽门关闭不全。结论幽门功能的损害和胃窦幽门十二指肠协调收缩障碍可能是功能性消化不良发病的重要机制     

Left ventricular diastolic flow dynamics in dilated cardiomyopathy: a color flow imaging and pulsed Doppler echocardiographic study

Left ventricular filling flow was evaluated at the mitral orifice and in the left ventricle (LV) using color flow imaging and pulsed Doppler echocardiography in seven patients with dilated cardiomyopathy (DCM) and 10 normal subjects. Using the apical approach, filling flow in early and late diastole was observed by two-dimensional color and M-mode color flow imaging, and flow velocity patterns at the mitral orifice and in the LV, 3 cm below the orifice, were analyzed by pulsed Doppler echocardiography. Color flow imaging disclosed slower movement of the inflow signals toward the apex in DCM than in the normal. With pulsed Doppler echocardiography, the delay in timing of peak velocity in the LV was distinctly greater in DCM than in the normal, although the mitral inflow velocity did not differ between DCM and the normal. The width of the filling flow, the rate of velocity reduction and the flow velocity in the LV did not differ between DCM and the normal. Thus, in DCM, the timing of filling flow in the LV is clearly delayed compared to the timing at the mitral orifice, and this cannot be explained solely by the mitral flow velocity pattern.     

新疆乌鲁木齐地区人群碘摄人量与甲状腺疾病的相关研究

目的 了解乌鲁木齐地区人群目前碘营养状况、甲状腺疾病流行情况并探讨两者的关系.方法 对新疆乌鲁木齐地区1693名成人进行体格检查、问卷调查,并测定平均尿碘中位数、甲状腺功能、甲状腺相关抗体和进行甲状腺B超检查.结果 在调查人群中,碘缺乏人数仅占9.5％,而碘过量人数达到30.0％.平均尿碘中位数达254.9 μg/L.碘充足/超足量组TT4水平明显高于其他两组[(9.02±2.63)对(7.69±2.85)、(8.45±2.13)μg/dl,均P＜0.05],碘缺乏组TSH水平显著高于其他两组[(3.00±1.86)对(2.37±1.91)、(2.27±1.86) mIU/L,均P＜0.01].各组甲状腺球蛋白抗体、甲状腺过氧化物酶抗体阳性率及甲状腺功能异常、甲状腺结节患病率没有统计学差别.结论 目前新疆乌鲁木齐地区碘缺乏状态已纠正,平均尿碘中位数254.9 μg/L.不同碘摄入状态人群甲状腺疾病患病率无统计学差别.     

Aortic flow patterns in normal neonates with patent ductus arteriosus: evaluation by Doppler color flow imaging

Serial Doppler echocardiography was performed in 12 normal neonates (0.5-4.0 hrs after birth) to evaluate flow patterns through the ductus arteriosus, and in the aorta and brachiocephalic artery. At the initial examination, flow through the ductus arteriosus was bidirectional in eight of the 12 neonates and continuously left-to-right in the remaining four. The bidirectional ductal shunts became continuous left-to-right flows within 11-21 hrs after birth in seven of the eight neonates and resolved by 29-47 hrs after birth. In the remaining four neonates, the continuous left-to-right shunts disappeared 14-36 hrs after birth. Systolic ejection flow patterns in the aorta and brachiocephalic artery had a triangular shape with the peak velocity in early systole, followed by a minimal flow reversal in all sites examined. Diastolic flow patterns in each arterial site were as follows: 1. In the ascending aorta, there was slow and sustained diastolic forward flow, which did not change with increasing age. 2. In the brachiocephalic artery, there was a pan-diastolic flow reversal in the neonates with bidirectional ductal flow (7/8). This pattern changed to slow pan-diastolic forward flow when the ductal changed to continuous left-to-right flow or when the ductal closure was confirmed. Most (3/4) of the remaining four neonates with continuous left-to-right ductal flow exhibited pan-diastolic forward flow. Another showed a pan-diastolic flow reversal 2 hrs after birth, which changed to pan-diastolic forward flow in the second examination 6 hrs after birth. 3. In the distal aortic arch, there was a pan-diastolic forward flow in all the neonates, and the velocity decreased when a closure of the ductus was confirmed. 4. In the descending aorta, there was a pan-diastolic flow reversal in neonates with bidirectional ductal flow (7/8). This reversal changed to pan-diastolic forward flow, when the ductal flow changed to continuous left-to-right flow or when the ductal closure was confirmed. In the remaining four neonates with continuous left-to-right ductal flow, two showed a pan-diastolic flow reversal at the initial examinations 2 to 3 hrs after birth. This became a pan-diastolic forward flow at the second examinations 6 and 12 hrs after birth. In the other two, there was a pan-diastolic forward flow which did not change. This pan-diastolic flow reversal observed in the brachiocephalic artery and descending aorta was closely related to the bidirectional ductal flow.(ABSTRACT TRUNCATED AT 400 WORDS)     

Role of color Doppler flow imaging in applicable anatomy of spleen vessels

AIM： To explore the role of color Doppler flow imaging （CDFI） in visualization of spleen vessels and to define its value for spleen micro-invasive operation. METHODS： A total of 36 patients requiring laparoscopic splenectomy （LS） for various hematopathies and autoimmune diseases were randomly selected from April 2005 to May 2008. Anatomic types of spleen pedicle, adjacent relations between spleen vessels and pancreas, diameters of spleen artery and vein were detected and recorded by preoperative CDFI. Different operative procedures were performed according to different anatomic frameworks. The parameters were recorded by telerecording during LS and compared with those by preoperative CDFI using Chi-square test. RESULTS： Two anatomic types of spleen pedicle and four different adjacent relations between spleen vessels and pancreas were detected by CDFI. The diameters of spleen artery and vein detected by CDFI were 0.46 ± 0.09 cm and 0.85 ± 0.35 cm, respectively. There was no statistical difference between the parameters recorded by CDFI and by telerecording （X^2 = 0.250, 0.677, P 〉 0.05）. LS was successfully performed following the anatomic information provided by preoperative CDFI.CONCLUSION： Different anatomic frameworks of spleen vessels can be provided by preoperative CDFI, which instructs micro-invasive operation of spleen and increase the safety of operation.     

Transesophageal color Doppler flow imaging in the evaluation of prosthetic cardiac valves

To determine the value of transesophageal echocardiography in the assessment of prosthetic cardiac valves, 11 patients with clinically suspected cardiac prosthetic valve dysfunction were studied by transesophageal two-dimensional imaging, as well as by color Doppler flow mapping. Among these 11 patients, there were 10 with biological tissue valves and 3 with metallic valves (1 Bjork-Shiley, 2 St. Jude). Nine patients had replacement of mitral valves alone. The remaining two had received both mitral and aortic prostheses. The degree of mitral regurgitation was graded by transesophageal color Doppler according to the area of the regurgitant jet visualized. The degree of aortic regurgitation was graded by the jet height/left ventricular outflow height ratio method. All transesophageal studies were performed without complication and all were well tolerated. The pathological morphology of the cardiac prosthesis was clearly visualized by transesophageal two-dimensional imaging and subsequently proven at surgery. Of those tested, one patient was found to have a torn leaflet, one had a dislodged leaflet, one patient had paravalvular leakage, four had cusp vegetations, and five patients had prosthetic degeneration for other reasons. Mitral regurgitation was graded as absent in one patient, mild in two patients, moderate in two patients, and severe in six patients. Aortic regurgitation was graded as severe in both patients with aortic prostheses. We conclude that in patients with clinically suspected cardiac prosthetic dysfunction, transesophageal two-dimensional imaging combined with color Doppler can provide reliable information that corresponds to surgical findings.     

彩色多普勒血流显像评价“肾通注射液”对急性肾功能衰竭家兔肾血流量的影响

目的　采用彩色多普勒血流显像评估“肾通注射液”对急性肾功能衰竭家兔肾血流量的影响。方法　 30只健康雄性大耳白兔分为正常组、模型组、肾通治疗组 ,每组 10只 ,肌注 5 0 %甘油等渗盐水制造急性肾小管坏死模型 ,正常对照组同法注射等容量生理盐水。造模后 1h,治疗组腹腔注射肾通注射液 (肾通组 ) ,正常组和模型组腹腔注射等容量 5 %葡萄糖 ,生化法监测肾功能 ,彩色多普勒血流显像动态观察各组家兔治疗后 2 4 h、4 8h、72 h肾血流动力学变化。结果　肾通组肾血流量较模型组显著升高 ,各级动脉阻力指数显著降低。肾功能各项指标均有显著改善。结论　“肾通注射液”可改善急性肾功能衰竭家兔肾血液供应 ,彩色多普勒血流显像可定量检测肾血流量