Contrast-enhanced power Doppler sonography in breast lesions: effect on differential diagnosis after mammography and gray scale sonography.

OBJECTIVE: To evaluate the efficacy of contrast-enhanced power Doppler sonography in the differential diagnosis of breast lesions after a mammography-gray scale sonography combination. METHODS: Sixty-eight patients with 69 breast masses underwent power Doppler sonography before and after intravenous injection of a contrast agent. The lesions were diagnosed as "highly suggestive of malignancy" (category 5; n = 32), "suspicious" (category 4; n = 21), and "probably benign" (category 3; n = 16) by mammography and gray scale sonography, modeled on the American College of Radiology Breast Imaging Reporting and Data System classification. Power Doppler findings did not affect patient treatment. The authors subjectively evaluated the estimated area of vascularity, degree of enhancement following contrast agent administration, morphologic features, and distribution of vessels within the lesions. RESULTS: The final diagnoses were malignant in 28 lesions and benign in 41. Significant enhancement after contrast agent injection was detected in both the malignant and benign groups. Only 2 criteria, estimated area of vascularity and degree of enhancement following contrast agent administration, proved to be significant diagnostic determinants for contrast-enhanced power Doppler sonography (P < .001; interobserver agreements, 74.4 and 77.8, respectively). Contrast-enhanced power Doppler sonography provided a higher specificity, positive predictive value, and negative predictive value than power Doppler sonography but a lower sensitivity and negative predictive value than mammography-gray scale sonography. Only in the category 4 lesions could the combination of mammography-gray scale sonography and contrast-enhanced power Doppler sonography accomplish a higher specificity (71%) and positive predictive value (70%) than mammography-gray scale sonography (39% and 53%, respectively). CONCLUSIONS: Power Doppler and contrast-enhanced power Doppler sonography cannot be recommended as confirmatory tests in Breast Imaging Reporting and Data System category 3 and category 5 lesions. Although contrast-enhanced power Doppler sonography may help reduce unnecessary biopsies in Breast Imaging Reporting and Data System category 4 lesions, recommendation of its use has many drawbacks, such as imperfectly established criteria, lack of absolute certainty, and high cost.     

多普勒声学造影与DSA检查对照观察兔肌肉VX2肿瘤血管的实验研究

目的与X线数字减影血管造影对比，探讨彩色多普勒和能量多普勒声学造影检测肿瘤血管特征的应用价值。方法将8只右侧股外侧肌肉种植有VX2肿瘤的新西兰大白兔经耳缘静脉注射自制的新型白蛋白氟碳声学造影剂，采用Acuson公司生产的Sequoia 512超声仪，分别应用彩色多普勒和能量多普勒显像观察肿瘤血管造影增强效果，并与DSA检查对照。结果二维超声检查8只荷瘤兔共发现病灶12个，呈圆形或类卵圆形，边界较清晰。造影后，肿瘤内血流显示率明显增高，血管形态变化明显，条状及分枝状血流数目增多，并有4例清晰显示滋养血管走行，与DSA检查结果相一致。结论彩色多普勒和能量多普勒声学造影(CDE)是检测肿瘤血流特征的重要手段。能量多普勒声学造影优于彩色多普勒造影显像。     

The role of power Doppler sonography in the evaluation of superficial soft tissue abscesses

Objective: To evaluate the efficacy of power Doppler ultrasonography in depicting increased vasculature and hyperemia around the superficial soft tissue abscess. Materials and methods: 21 patients with soft tissue abscess were evaluated with gray scale imaging, color Doppler sonography, power Doppler sonography and computed tomography. In each case attempts were made using power Doppler sonography to demonstrate any areas of increased vascularity around the lesion. The results were compared with computed tomographic findings. Results: Peripheral hyperemia and increased vasculature were demonstrated with power Doppler sonography in 19 of 21 patients with soft tissue abscess. The hyperemic area demonstrated around the wall of the abscess by power Doppler sonography was similar to the enhanced area shown by computed tomography performed after contrast administration. Conclusion: Power Doppler sonography shows increased vasculature and hyperemia in the wall of abscesses. Therefore, power Doppler sonography can be used to assist with the diagnosis of superficial soft tissue abscess.     

Correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis.

OBJECTIVE: To record the correlation between color power Doppler sonographic measurement of breast tumor vasculature and immunohistochemical analysis of microvessel density for the quantitation of angiogenesis. METHODS: Women with palpable breast masses scheduled for excision biopsy were scanned with two- and three-dimensional color power Doppler sonography before and after the administration of a sonographic contrast agent. Vessel counts were performed on two- and three-dimensional sonographic images before and after contrast agent administration. All tumors were surgically removed and underwent immunohistochemical analysis for microvessel density assessment. The sonographic measure of tumor vascularity was correlated with microvessel density. RESULTS: Pathologic examination showed 43 breast cancers and 14 benign breast masses. Higher microvessel density was noted in malignant than benign breast masses (P < .0005). Color power Doppler sonographic measurement of tumor vessel number showed a significant positive correlation with tumor size (P < .05) and progesterone receptor negativity (P < .05). A significant positive correlation was observed between microvessel density and the number of intratumoral blood vessels assessed by both two- and three-dimensional color power Doppler sonography (P < .05). Regression models showed three-dimensional color power Doppler sonography to have a significantly higher correlation with microvessel density when compared with two-dimensional color power Doppler sonography at baseline (P < .005). The administration of a sonographic contrast agent did not improve correlation with microvessel density. CONCLUSIONS: A significant correlation was shown between color power Doppler sonographic measurement of tumor vascularity and microvessel density by immunohistochemical analysis. Further improvement in Doppler sonographic techniques to map capillary vessel flow should be explored to improve the current association with pathologic findings.     

Evaluation of solid breast lesions with power Doppler sonography.

PURPOSE: We compared the abilities of power and conventional color Doppler sonography to depict the vascularity of solid breast lesions and evaluated the usefulness of power Doppler sonography in differentiating between benign and malignant breast lesions. METHODS: One hundred two solid breast lesions (59 benign and 43 malignant lesions) were studied with power and color Doppler sonography. Power and color Doppler sonograms were retrospectively compared for the depiction of blood flow signals. Power Doppler images were also reviewed for the amount of Doppler signals, pattern of vascularity, and morphology of vessels. The sensitivity, specificity, and accuracy of the 2 techniques were calculated. RESULTS: Compared with color Doppler sonography, power Doppler sonography depicted flow superiorly in 61 cases (60%) and equally in 41 cases (40%). On power Doppler sonography, the incidence of marked blood flow in malignant lesions (65%) was higher than that in benign lesions (39%). The pattern of vascularity was predominantly central (86%) and/or penetrating (65%) more often in malignant lesions than in benign lesions (51% and 34%, respectively). Branching (56%) and disordered vessels (42%) were seen more often in malignant lesions than in benign lesions (22% and 8%, respectively). The sensitivity, specificity, and accuracy in diagnosing malignancy were 64%, 76%, and 71%, respectively, for power Doppler sonography and 77%, 76%, and 76% for color Doppler sonography. CONCLUSIONS: Power Doppler sonography was more sensitive than color Doppler sonography in the detection of flow in solid breast lesions. Although power Doppler sonography was not more effective in diagnosing malignant lesions, central and penetrating vascularity patterns and branching and disordered vessels seem to be helpful findings in predicting malignancy.     

Contrast-enhanced power Doppler sonography of ductal pancreatic adenocarcinomas: correlation with digital subtraction angiography findings

PURPOSE: The purpose of this prospective study was to utilize contrast-enhanced power Doppler sonography to evaluate the enhancement characteristics of ductal pancreatic adenocarcinomas and correlate them with the tumor vascularity observed on digital subtraction angiography (DSA). METHODS: Twenty consecutive patients with ductal pancreatic adenocarcinoma underwent power Doppler sonography and DSA. Tumor vascularity was assessed using unenhanced and contrast-enhanced power Doppler sonography. The contrast agent Levovist was administered intravenously by bolus injection of a dose of 2.5 g at a concentration of 350 mg/mL; saline was administered immediately thereafter. The patients were asked to hold their breath for 30 seconds (for the period 15-45 seconds after saline injection) while the early phase of enhancement was studied; the delayed phase of enhancement was observed between 60 and 120 seconds after saline administration, while patients breathed gently. RESULTS: None of the 20 pancreatic carcinomas showed any color signals on power Doppler sonography before administration of the contrast medium. Seventeen (85%) of the 20 pancreatic carcinomas also showed no enhancement in the early and delayed phases of contrast-enhanced power Doppler sonography. However, in the early phase of contrast-enhanced power Doppler sonography; 1 lesion showed pronounced enhancement and 2 showed mild enhancement. On DSA, the 17 carcinomas showing no enhancement on power Doppler sonography were found to be hypovascular, whereas the remaining 3 carcinomas with contrast enhancement on power Doppler sonography were found to be hypervascular. CONCLUSIONS: The enhancement characteristics of the ductal pancreatic adenocarcinomas correlated well with the tumor vascularity observed on DSA. However, further study is needed to determine the accuracy of contrast-enhanced sonography in the diagnosis of pancreatic masses.     

The role of enhanced Doppler ultrasound in differentiation of benign vs. malignant scar lesion after breast surgery for malignancy.

AIM: To evaluate the benefit of echo-contrast-enhanced Doppler sonography in the differentiation of benign vs. malignant breast lesions after surgical removal of a malignant breast mass. METHODS: Thirty-eight patients referred for biopsy of a palpable, suspicious scar lesion 1-15 years (mean 3.3 years) after surgery for breast cancer were examined. During baseline ultrasound examination a subjective scoring system of the vascularity, the number, the regularity of vessels' course and their Doppler parameters were assessed. After injection of an ultrasound contrast agent (Levovist) the same scoring system was applied to the parameters together with enhancement kinetics, enhancement intensity and enhancement pattern. Any increase in the scoring level of two or more characteristics (vascularity, number of vessels, intensity of enhancement in the tumor or regularity score of vessels in the lesion) was defined as suspicious for malignancy. A marked increase of enhancement in the immediate tumor periphery was also regarded as suspicious for malignancy. The sonographic results were assessed prospectively and correlated with the histology of the lesion. RESULTS: Of the 38 patients with a clinically-suspicious scar lesion, there were 28 true scars and 10 malignant scar lesions. All scar lesions showed no or slight vascularity on baseline sonography. After Echocontrast-enhancement a significant increase in tumor vascularity and the number of tumor vessels could be demonstrated in all 10 malignant lesions but in only one of the 28 benign scars. CONCLUSION: Scars pose inherent technical problems for optimal mammography. Sonographic evaluation of the vascularity of the lesion with contrast enhancing agents showed improved diagnostic accuracy in the hands of an experienced examiner.     

Usefulness of power Doppler and contrast-enhanced sonography in the differentiation of hyperechoic renal masses

Background: In a prospective study, we compared power Doppler with and without contrast medium in the depiction of vascularity for the characterization of hyperechoic renal lesions. Methods: Forty-one hyperechoic renal expansive lesions (29 benign, 12 malignant) in 32 patients were studied with power-Doppler ultrasonography before and after administration of an echo-enhancing agent (Levovist Schering AG, Berlin, Germany). Vascular architecture of the lesions was categorized into five different patterns. Results: Power Doppler ultrasonography showed vascular structures in 25 lesions. The study enhanced with Levovist showed vascularity in eight of 16 lesions not seen on the unenhanced study. The characterization of vascular patterns with unenhanced power Doppler ultrasonography improved diagnostic accuracy compared with gray-scale ultrasonography (59% vs. 32%). The combination of B mode and power Doppler produced even greater diagnostic accuracy (78%), independent of the administration of echo-enhancing agent. Levovist administration was useful in the differential diagnosis between pseudotumor and neoplasm. Conclusion: The use of songraphic contrast agent did not increase the diagnostic accuracy of power Doppler in the differential diagnosis of hyperechoic renal lesions but was advantageous for the characterization of suspected pseudomasses. Received: 6 September 2000/Accepted: 13 December 2000     

Detection of bleeding in injured femoral arteries with contrast-enhanced sonography.

OBJECTIVE: The purpose of this study was to investigate the feasibility of detecting acute arterial bleeding by means of contrast-enhanced sonography. METHODS: Puncture injury was produced transcutaneously with an 18-gauge needle in 26 femoral arteries (13 in the control group and 13 in the contrast-enhanced group) of rabbits. A sonographic contrast agent (Optison; Mallinckrodt Inc, St Louis, MO) was administered intravenously at a dose of 0.06 to 0.07 mL/kg. Sonography of the femoral arteries was performed before and after injury, both before and after injection of Optison, with B-mode imaging, color Doppler imaging, and pulse inversion harmonic imaging (PIHI). RESULTS: The specific location of active bleeding could not be visualized in B-mode and PIHI scans in the control group (no Optison injection). After administration of Optison, the bleeding site was visualized because of the increased echogenicity of the extravasated blood at the puncture site in both B-mode imaging and PIHI. In color Doppler images, bleeding sites were localized successfully in 84.6% of the cases in the presence of Optison and in 30.8% of the cases without Optison. Histologic examination (light microscopy) of the hematoma confirmed the presence of contrast agent microbubbles in the extravascular space surrounding the artery. CONCLUSIONS: Contrast-enhanced sonography may provide an effective method for detecting arterial bleeding.     

Contrast-enhanced ultrasound for guidance of local tumor ablation

The objective was to assess the efficacy of sonography with and without contrast medium enhancement in guiding and monitoring percutaneous ethanol ablation of tumors in an animal model. VX-2 carcinoma was implanted into the thighs of New Zealand white rabbits and examined by grey-scale ultrasound, color, power, and pulse Doppler, before and after injection of 95% ethanol into the tumors. Injections of ethanol were guided by ultrasound to sites of tumor vascularity, until all tumor vascularity had been obliterated. Microbubble contrast medium or saline was injected i.v. prior to each of the ultrasonic interrogations. Arteriography was performed before and after ablation. Selected tumor samples were submitted for histologic examination. Contrast enhanced tumor vascularity over saline controls in all cases. In some, incompletely ablated foci of tumor could only be identified with contrast medium enhancement. Arteriography showed complete ablation of all but 1 tumor. We conclude that ultrasound enhanced by contrast better shows the presence or absence of tumor vascularity. Ultrasound enhanced by contrast might offer an accurate means of guiding and monitoring percutaneous ethanol injection for tumor ablation.     

Low-intensity ultrasound application in distal radius metaphyseal bone defects of dogs

We assessed the repair of transverse, 3-mm wide bone gaps created at the distal radius in 28 dogs that were randomly divided into two 14-animal groups; one was the control group and the other received a daily, 20-min application of low-intensity pulsed ultrasound for 100 days. Sequential radiographs, histomorphometrics, bone fluorescent histology and bone vascularity assessments found that all animals from both groups obtained a stage of hypertrophic-type nonunion with fibrocartilage tissue formation throughout the region of osteotomy. However, treated animals exhibited areas of endochondral ossification within the fibrocartilage region. There was no difference in type of vascularity or the newly formed bone process obtained by tetracycline labeling. Application of low-intensity ultrasound was not capable of significantly changing the reparative process and it may not be sufficiently powerful to overcome a combination of local deleterious effects on bone healing, created by gapping, excessive motion and periosteal resection.     

Multiparametric Sonography of Hematologic Malignancies of the Testis: Grayscale,Color Doppler,and Contrast‐Enhanced Ultrasound and Strain Elastographic Appearances With Histologic Correlation

Primary testicular lymphoma is rare and appears with nonspecific findings on grayscale and color Doppler sonography. We present 8 patients further examined with contrast‐enhanced sonography, strain elastography, and histologic analysis after orchiectomy. Seven of 8 patients had a diagnosis of large B‐cell lymphoma, and 1 of 8 had a diagnosis of granulocytic sarcoma, with solitary lesions (2 of 8), multiple lesions (3 of 8), or entire testicular involvement (3 of 8). Lesions appeared hypoechoic (7 of 8) or isoechoic (1 of 8), all with increased vascularity on color Doppler sonography and a nonbranching linear pattern of intratumoral vessels (7 of 8). Contrast‐enhanced ultrasound (CEUS) confirmed this pattern and showed increased enhancement in all lesions. On strain elastography, all lesions were hard, with an elasticity score of greater than 4. Multiparametric sonography of testicular lymphoma identifies increased vascularity on color Doppler and contrast‐enhanced ultrasound and increased lesion stiffness on strain elastography.     

Sonographic depiction of changes of tumor vascularity in response to various therapies

PURPOSE: To evaluate the diagnostic accuracy of power Doppler sonography for the depiction of changes in tumor vascularity with various therapeutic regimens. MATERIALS AND METHODS: Tumor cells were implanted subcutaneously in thirty-two mice and assigned to four treatment groups: control, radiation therapy, antiangiogenesis therapy (VEGF [vascular endothelial growth factor] receptor antagonist, SU11248), or combined antiangiogenesis and radiation therapy. Twenty of these mice were scanned with power Doppler sonography at two time points over the course of treatment, and power-weighted pixel densities were assessed. The other twelve mice each underwent subcutaneous placement of a dorsal skin-fold window over the tumor site, allowing for daily angiogenesis assessment of vascular length density. All tumor specimens had correlative histologic analyses performed, including immunohistochemical stains for microvasculature. RESULTS: Sonographic measurements revealed significant longitudinal differences in tumor vascularity among the four treatment groups: control mice receiving no treatment demonstrated a doubling in intra-tumor color pixel density (P < 0.02); those receiving radiation alone increased by 68% (P < 0.04); those receiving oral therapy alone increased by 44% (P = 0.016); and those receiving combination therapy decreased by 38% (P < 0.02). Tumor vascularity independently measured in the twelve mice with the skin-fold windows revealed a similar response to each type of treatment. Post-mortem tumor histology was consistent with both sonographic and skin-fold window measurements. CONCLUSION: Power Doppler sonography was accurate and reliable in measuring tumor vascularity changes in this model. These results were independently confirmed by a quantitative method relying on direct visualization of the microvasculature. Because it is rapid and non-invasive, sonographic quantification is beneficial in assessing the anti-angiogenic effects of various treatment strategies for cancer.     

经静脉声学造影诊断下肢动脉病变的初步研究

目的：探讨经静脉声学造影诊断下肢动脉病变的应用价值,方法：12例患者接受造影检查,造影剂经左前臂静脉注射,结果：注射造影剂后,下肢动脉彩色血流信号增多,血流束增宽,8例股,Guo动脉得造影前闭塞段及其远侧血管均无彩色血流信号,造一闭塞段仍无彩色血流信号,但远侧2例胫前动脉和6例胫后动脉有细窄彩色血流束,并可见侧支血流汇入,另4例股,国动脉狭窄者,造影前3例胫前动脉和2例胫后动脉无彩色血流信号,但造影后仅2例胫产动脉无彩色血流信号,4例胫后动脉均有彩色血流,结论：经静脉超声造影有助于准确诊断下肢血管病变。     

Contrast-enhanced power Doppler sonography for the differentiation of cystic renal lesions: preliminary study.

The objective of this study was to investigate the potential usefulness of contrast-enhanced power Doppler ultrasonography in the differentiation of benign and malignant cystic renal lesions. Our study group was limited to patients who had complex cystic renal lesions of uncertain malignancy at screening ultrasonography. During the previous 6 months, 485 patients have been referred to ultrasonography for evaluation of renal cystic lesions, but only 13 patients participated in this study. Focusing on tumor vascularity in the intracystic septa or solid component, we analyzed power Doppler sonographic images before and after intravenous injection of contrast agent and compared them with contrast-enhanced CT scans or MR images and pathologic results. The visualization of vascularity was best on contrast-enhanced power Doppler sonography (n = 7). The use of contrast agent with power Doppler sonography showed improved diagnostic accuracy (77%) that was superior to non-contrast-enhanced power Doppler sonography or contrast-enhanced CT. In conclusion, contrast-enhanced power Doppler sonography provides better visualization of tumor vascularity in complicated cystic renal lesions than other imaging modalities, leading to more exact differential diagnosis. We therefore expect that this imaging modality might be very useful in differential diagnosis of problematic cystic renal lesions, benign or malignant.     

Power Doppler sonography in the diagnosis of Graves' disease.

In addition to color and pulsed Doppler sonography findings, we aimed to describe power Doppler sonography findings in Graves' disease in this study. Twenty-three patients with Graves' disease were imaged with gray-scale, color and power Doppler sonography. Twenty normal volunteers were examined by the same equipment and the same technique as a control group. A subjective grading system was used to categorize the vascularization in pulsed Doppler sonography images from normal to markedly increased vascularization. Power Doppler sonography exhibited diffuse hypervascularity in the thyroid gland in all patients. The flow was covering about all the parenchyma. Four patients showed mild, 12 patients moderate and seven patients marked vascularity. The intensity of power Doppler flow pattern was not correlated with the severity of the disease. This study demonstrated that power Doppler sonography is a convenient, time saving, inexpensive and noninvasive method as compared with isotope scan and some other laboratory tests for confirmation of Graves' disease.     

Ultrasound diagnosis of uterine arteriovenous fistula associated with placental site trophoblastic tumor.

We report a case of a woman with abnormal vaginal bleeding who had a placental site trophoblastic tumor (PSTT) detected following hysterectomy. Surgery was performed because of a large uterine arteriovenous fistula detected by transvaginal color and pulsed Doppler sonography. Color Doppler sonography revealed a lacunar-type lesion with a marked increase in uterine vascularity, and pulsed Doppler sonography demonstrated a low resistance index. This vascular pattern indicated the formation of blood lacunae and arteriovenous shunts caused by PSTT within the uterine myometrium. This is the first report to describe the ultrasound findings in a case of PSTT complicated by a uterine arteriovenous fistula.     

Contrast-enhanced power Doppler sonography: assessment of revascularization flow in Legg-Calvé-Perthes' disease

A total of 26 children (26 affected, 25 control hips) with Legg-Calvé-Perthes' disease (LCP) met the cooperation requirements for inclusion in the study using contrast-enhanced power Doppler sonography for assessment of changes in the revascularization flow. Sagittal sonograms were obtained before and at the peak effect of an intravenously injected microbubble-based contrast agent. Overall mean peak enhancement ratios were greater for children with later onset of disease (>5.8 years old) than for those with earlier onset (< or = 5.8) (p = 0.02). The use of ultrasound (US) contrast agents improved depiction of proximal femoral vascularity in all regions of the femoral head: epiphysis (n = 3, pre; n = 8, postcontrast), physis (n = 12, pre; n = 21, postcontrast) and metaphysis (n = 6, pre; n = 8, postcontrast) and resulted in a marked increase in the number of mean pixel intensity values within the physis (p = 0.02). In conclusion, contrast-enhanced power Doppler sonography is an effective method for demonstration of changes from the revascularization process in LCP, particularly within the physis.     

Monitoring of fracture calluses with color Doppler sonography

PURPOSE: Fracture callus formation is closely associated with vascular invasion, and the use of color Doppler sonography has been suggested as a means to monitor, earlier than gray-scale sonography, the first stages of the healing process. We report the findings in a series of patients with tibial fractures in whom both gray-scale sonography and color Doppler imaging were employed to monitor new bone formation at the fracture site. METHODS: Twenty patients with tibial fractures treated with external fixator frames were examined sonographically about 10 days after surgery and then about every 25 days until radiographic demonstration of consolidation. RESULTS: Eighteen of 20 patients had a well-developed callus, while the remaining 2 patients showed delayed fracture healing. In patients with normal callus development, color Doppler imaging demonstrated the progressive formation of new vessels until about 100 days from the surgery; at subsequent examinations, flow signals decreased, and bone remodeling was confirmed by conventional radiography and gray-scale sonography. The resistance indices in these patients tended to decrease in the early weeks after surgery and then slightly increased. In contrast, lack of development of flow signals and persistence of high resistance indices were observed in the 2 patients with delayed fracture healing. CONCLUSIONS: Color Doppler sonography seems to have the capability to predict whether the development of fracture calluses will be normal or delayed.     

Decreased muscle blood flow in fibromyalgia patients during standardised muscle exercise: a contrast media enhanced colour Doppler study.

The aim of the study was to investigate if contrast enhanced ultrasound (US) imaging of muscular blood flow during and following exercise could detect alterations in vascularity in fibromyalgia (FM) patients. Ten FM patients and 10 matched controls were examined with US during standardised static and directly following static and dynamic muscular contractions of the infraspinatus muscle. Doppler ultrasound evaluation was performed before and after the administration of ultrasound contrast media. The FM patients had lower magnitude of muscle vascularity following dynamic (p<0.001) and during (p<0.002) static exercise compared to controls. The immediate flow response to muscular activity was not only of a lower magnitude, but also of a shorter duration in FM patients following dynamic exercise (p<0.001) and during static exercise (p<0.01). There were no statistically significant group differences in blood flow intensity or duration following static contraction. In conclusion, contrast enhanced US was found useful to study real-time muscle blood flow changes during and following standardised, low-intensity exercise in FM patients and healthy controls. Our results support the suggestion that muscle ischemia can contribute to pain in FM, possibly by maintaining the central nervous changes such as central sensitisation/disinhibition. US with contrast can be a new valuable approach to assess muscle perfusion in pain patients during standardised exercise.