European journal of ultrasound : official journal of the European Federation of Societies for Ultrasound in Medicine and Biology最新文献

The rete testis is formed in the fifth week of intra-uterine life. The epithelium along the medial side of the mesonephric ridge thickens to form a genital ridge; cellular gonadal cords at the periphery of the ridge unite with a tubular network from the mesonephric mesenchyme forming the testicular rete. On ultrasound, a range of normal appearances of the rete testis is recognised from ill-defined areas of decreased reflectivity to a coarse tubular appearance (often with finger like projections). In the present review the embryological development of the rete testis is briefly outlined. In addition, the important anatomical variations, pertinent to ultrasound imaging, will be presented.

Most of the published studies concerning platelet aggregation were performed with chemical stimulation procedures, however, mechanical stimulation might be a better simulation of physiological activation of platelets. In order to evaluate the influence of ultrasound on platelet aggregation in vitro, we developed an ultrasound device in a standardized set-up, and we evaluated the influence of lipoproteins and the glycoprotein IIb/IIIa inhibitor tirofiban on ultrasound induced platelet aggregation. A cylindrical shaped plastic test tube with 1 ml of platelet-rich plasma was placed in an ultrasound bath (35kHz) for 5 s. The ultrasound energy transfer into the sample (ΔW=3.77 J) was calculated using the average temperature increase (averaged by 0.935 °C) of the sample. Platelet aggregation was quantified immediately after stimulation with ultrasound or adenosine diphosphate (ADP 2.1 and 4.2 μM) by the Myrenne Aggregometer PA2 at low (40 s⁻¹) and afterwards at high (2500 s⁻¹) shear. To evaluate the influence of lipoproteins, seven healthy male volunteers were investigated before and after a fat load (50 g fat per m² body surface), and 11 patients suffering from hypercholesterolemia and atherosclerotic disease before and after a single low-density lipoprotein (LDL) apheresis. Platelet aggregation after ultrasound stimulation was well correlated with platelet aggregation after ADP (r between 0.50 and 0.95). However, when exposed to high shear, the low shear-induced platelet aggregates were more stable after ultrasound stimulation compared with ADP stimulation either with or without tirofiban. After the fat load triglyceride concentration increased from 0.86±0.39 to 2.10±1.10 mmol l⁻¹ (P<0.05) resulting in a reduced formation of platelet aggregates after weak (ADP 2.1 μM) but not after strong (ADP 4.2 μM or ultrasound) stimuli. After a single LDL apheresis LDL cholesterol dropped from 3.99±0.90 to 1.06±0.55 mmol l⁻¹ (P<0.005). No changes in platelet aggregation were observed with the exception of a lower aggregation when exposed to high shear after stimulation with 2.1 μM ADP. In conclusion, we found the ultrasound stimulation of platelet-rich plasma easy to perform. The platelet aggregation after ultrasound stimulation correlated well with stimulation after ADP. While a reduction in LDL cholesterol concentration had only slight effects on platelet aggregation, an increase in triglyceride concentration resulted in a reduced formation of platelet aggregates after weak stimulation.

Objective: With continuous improvements in ultrasound technology, small vessels with remarkably slow blood flow that may not be assessed by color Doppler ultrasonography, can be evaluated using power Doppler ultrasonography. In the present study, penile arterial anatomic variations were determined with power Doppler ultrasonography and its impact on penile hemodynamic status. Methods: A total of 54 patients with erectile dysfunction were evaluated with power Doppler ultrasonography. The effects of vascular anatomic variations and the structure of the corpora cavernosa and tunica albuginea on vascular status were assessed on both sides. Results: A normal penile vascular system was observed in 35.2% and 25% of 54 patients (mean age: 46.6±11.5 years) at the radix and mid-shaft of the penis, respectively. Pure arterial component was observed in 40.7% (22/54) and 47.2% (17/36) of the patients at the base and mid-shaft of the penis, respectively. Penile arterial insufficiency was severe in 9.2 and 5.5% of the patients at the base and mid-shaft of the penis, respectively, whereas intrapenile truncus was found in six patients (5.5%), the ratio of single cavernosal artery, intrapenile and extrapenile bifurcations were 69.4, 7.4 and 12.0%, respectively. Twenty (18.5%) dorso-cavernosal perforators, 15 (13.9%) cavernoso-dorsal and 30 (27.8%) intercavernosal branches were found. Peak systolic blood flow velocity values were decreased in 12 of 36 patients (33.3%) distally, while increased blood flow was observed in 11 (30.5%). Conclusions: Hemodynamic parameters might be variable at either side of the penis and depend on intrapenile arterial anatomic variations. Parameters determined using power Doppler ultrasonography should be evaluated from the proximal to distal side of the penis to obtain reliable and standard results. However, variations of penile arterial anatomy and its effect on penile hemodynamic changes should not be overlooked especially in the patients who are candidates for penile reconstructive or vascular surgery.