超声波治疗疼痛触发点的研究现状

大多数颈肩腰腿痛都与肌筋膜疼痛触发点的产生及活化有关,而对于其治疗手段也是多种多样。相对于传统的注射技术和针法,超声波治疗技术因其无创、经济、安全及有效被广泛用于疼痛触发点的临床治疗。本文通过阅读大量的文献,对超声波治疗疼痛触发点的研究现状进行综述。     

脂肪肝的CT及B超诊断

目的：探讨ＣＴ及Ｂ超检查对脂肪肝的诊断价值及特征性表现。方法：作者回顾分析了脂肪肝的９８例ＣＴ及７８例Ｂ超资料。结果：９８例ＣＴ中肝内血管及腹膜显影各３６例；７８例Ｂ超中３３例肝内血管回声减弱，２３例纤维隔回声减弱。结论：ＣＴ中腹膜显影原因在于肝脏密度的减低。根据ＣＴ中肝密度减低程度、肝脾ＣＴ值之比、肝内血管显示、肝表面腹膜显影程度将脂肪肝分成三级。Ｂ超中相应有肝回声增强光点密集程度、肝内血管纤维隔回声减弱程度的三级改变。据此可对脂肪肝病变程度、肝功能实质状况做出估价，对临床治疗及预后均有重要参考价值。     

实时超声显象诊断卵巢肿瘤的探讨：附211例报告

分析了经手术和病理证实的211例卵巢肿瘤的超声检查结果。其中良性186例,恶性25例。超声检查良性符合率93.5％(174/186),恶性符合率92％(23/25)。超声直接提示病理诊断良、恶性符合率分别为84.4％(157/186)和68％(17/25)对卵巢肿瘤的组织形态学表现与声象图特点及鉴别诊断进行了讨论。     

三维超声在前列腺疾患诊断中的应用：（附301例报告）

应用奥地利Ｃｏｍｂｉｓｏｎ３３０型三维超声诊断仪经腹、经直肠同时观察３０１例前列腺获得高质量的前列腺声象图。直肠途径（ＴＲＡ）超声显像准确率１００％，明显高于腹壁途径（ＴＡＡ），前者能够清晰显示前列腺内部结构；直观尿道排尿发现尿道梗阻动态变化与前列腺体积不成正比，与增生结节压迫程度及部位有关；由于在同一部位可取得三个径线，并自动计算而使前列腺体积测量准确性提高。     

Local hyperthermia induced by focussed and overlapping ultrasonic fields—An in vivo demonstration

Axial temperature distributions were measured in living and post mortem porcine tissues during sonication with plane, focussed and overlapping ultrasonic fields. With the focussed field it was always possible to induce the temperature maxima at depths up to 50 mm, although the actual temperatures achieved varied from animal to animal. The plane 0.75 MHz transducer produced a maximum temperature close to the skin surface. With 7 overlapping plane fields a relatively uniform temperature distribution was produced in a large tissue volume. The blood perfusion in tissue has a significant effect not only on the magnitude of the temperature increase, but also on the temperature distribution.     

Characterisation of in vivo placental ultrasonic images using digital techniques-a preliminary report

Computer analysis of the digitized ultrasonic waveform from in vivo placentae (14–40) weeks gestation has been used to quantify the B-scan appearance. The amplitude distribution of echo peaks detected from the video waveform is described by two parameters, coefficient of variation and skew. Both indices correlate with B-scan appearance (p<0.001) for a group of 22 patients. The results of 92 scans suggest that the texture index value reflects the degree of calcification and fibrin deposition in the tissue. The texture indices of second trimester placentae (14–18 weeks gestation, n = 20) correlate with the development of hypertension later in pregnancy (p<0.05).     

Computer based pattern recognition of carotid artery Doppler signals for disease classification: prospective validation

A computer based pattern recognition method has been developed to classify the percent diameter reduction in nonoccluded internal carotid arteries. Using a combined B-mode/pulsed Doppler unit, the system utilizes spectral waveforms obtained from the low common and proximal internal carotid artery locations. The ECG-R wave is used as a time reference to synchronize the averaging of Doppler spectra from 20 heart cycles. An averaged waveform is generated and represents the spectral data from which features are extracted for analysis. A stepwise selection algorithm identifies a feature subset for partitioning the entire range of disease into two states, less than and greater than a decision point. Three such partitions are made, leading to the following categories: Normal, 1-20, 21-50 and 51-99% dia. reduction. A classifier was trained, tested prospectively against unknown data and the results compared to angiography. Of the 170 vessels tested, 141 (82%) were classified in the same category by angiography and the computer system. Agreement for each category was 93% (27/29) for the normals, 81.5% (44/54) for the 1-20% lesions, 78% (29/37) for the 21-50% lesions and 82% (41/50) for the 51-99% lesions. The computer method and angiography differed by more than one category in only one of the 170 tests. The level of agreement corrected for chance (Kappa +/- SE(K] was 0.769 +/- 0.039. Future efforts will be directed toward dividing classification of disease further (especially in the 51-99% category), developing a dedicated microprocessor for on-line analysis of the signals and using the system for prospective epidemiological studies of various populations.     

Variability and reproducibility of arterial Doppler waveforms

The variability and reproducibility of arterial Doppler waveforms are influenced by factors such as operator experience, physiological changes in the patient, and the type of Doppler processing system. Some aspects of these were studied using Laplace transform analysis of waveforms from the femoral and posterior tibial arteries of normal subjects and arteriopaths.Five consecutive waveforms were obtained from the femoral and posterior tibial arteries of normal subjects during about 1 hr of supine rest. Group 1 (n = 20) was studied 9 months before Group 2 (n = 11), early in the operator's experience of waveform recording. Variability (root mean square) of femoral and posterior Laplace 6 decreased from 16.9 to 12.5%, and 23.3 to 17.9% respectively (P < 0.05 in each case). In arteriopaths (n = 8) there was a trend to more variable results at femoral level (only significant in the case of Laplace ω₀ - P < 0.05), while posterior tibial results tended to be less variable. Normal subjects examined in the longer term (n = 4), with a mean interval of 28 days between recordings, did not show significantly greater variability than those examined over 1 hr.There was no significant difference in variability of results in normal subjects (n = 30) using instantaneous average Doppler processing compared with maximum frequency processing, except in the case of posterior tibial Laplace ω₀ (maximum frequency more variable - P < 0.05).     

Effects of ultrasound on Drosophila—II. The heating mechanism

An exposure of the eggs of Drosophila melanogaster to a traveling wave of 1 MHz ultrasound at 5 W/cm² for 30 sec has been found to kill approximately 70% of the population. To determine whether heating could be responsible for this effect, the sensitivity of the eggs to heat alone was tested. Temperature increments attributable to ultrasound were estimated by treating the eggs as heat sources in a thermally conducting medium. The absorption coefficient of the eggs was found to be very large but estimated to be less than 5 nepers/cm. The corresponding maximum temperature increments were calculated to be less than 3°C. This value is far too low to account for the observed effects on the basis of heating.     

Unusual intrauterine objects: potential pitfalls in ultrasonographic identification.

Three cases of echogenic objects in the uterine cavity are reported. These objects had ultrasonographic characteristics of contraceptive intrauterine devices (IUDs) and, in the absence of patients' medical histories, would almost certainly have been wrongly identified as such. The authors demonstrate that noncontraceptive intrauterine objects can mimic IUDs.