Contrast-enhanced two- and three-dimensional sonography for evaluation of intra-abdominal hemorrhage

Contrast-enhanced ultrasound-guided thrombin injection in the management of iatrogenic pseudoaneurysm (PSA): A case report and review of literatures

Pseudoaneurysm (PSA) formation is the most common arterial complication of endovascular procedures requiring arterial puncture. The present study reported a case of a 72-year-old male patient with iatrogenic femoral artery PSA treated with contrast-enhanced ultrasound (CEUS)-guided thrombin injection. Conventional ultrasound (US) and CEUS were used to diagnose, guide treatment, and evaluate the treatment efficacy. In the case, the PSA was successfully occluded with 1000 IU of thrombin. During the follow-up after 48 hours of thrombin injection, US found that the PSA had complete thrombosis without arterial supply. No complications occurrence in the course of the treatment. CEUS-guided thrombin injection for the treatment of PSA was effective and safety and the associated literatures were also reviewed.

Application of Contrast-Enhanced Real-time 3-Dimensional Ultrasound in Solid Abdominal Organ Trauma

OBJECTIVES

To determine whether real-time 3-dimensional ultrasound (RT3DUS) could provide additional information on early detection and evaluation in the management of solid abdominal organ trauma based on an animal model.

METHODS

Nine bleeding lesions were developed in the livers (n = 3), kidneys (n = 3), and spleens (n = 3) from 9 pigs. An ultrasound contrast agent was administered intravenously (liver, 0.025 mL/kg; kidney, 0.008 mL/kg; and spleen, 0.013 mL/kg) after an unenhanced 2-dimensional ultrasound (2DUS) examination (B-mode and color Doppler). After contrast agent injection, bleeding lesions were imaged by 2DUS and sequentially imaged by 3-dimensional static ultrasound (3DSUS) and RT3DUS to identify active bleeding, observe the relationship between bleeding lesions and peripheral blood vessels, and evaluate the spatial scope of the bleeding lesions in the organs.

RESULTS

For the identification of active bleeding, there was no statistical difference in contrast-enhanced 2DUS, 3DSUS, and RT3DUS. For observation of the relationship between bleeding lesions and peripheral blood vessels, RT3DUS performed statistically better than 2DUS (P < .05), as reconstructed RT3DUS could show more information about the relationship. For the evaluation of the spatial scope of the bleeding lesion in the organ, RT3DUS also performed statistically better than 2DUS from the multiplanar observation by postprocessing of the 3-dimensional real-time volumes (P < .05).

CONCLUSIONS

Real-time 3-dimensional ultrasound improves early detection and evaluation of solid abdominal organ trauma and provides additional information over the current contrast-enhanced 2DUS.

Added value of contrast-enhanced ultrasound (CEUS) with Sonovue® in the diagnosis of inferior epigastric artery pseudoaneurysm: report of a case and review of literature

The anatomical position of the inferior epigastric artery (IEA), within the rectus sheath, subjects patients to possible IEA injury during abdominal wall surgical and interventional procedures. Pseudoaneurysm arising from IEA is very uncommon with only 16 cases reported in the literature. We present a case of an IEA false aneurysm resulting from therapeutic paracentesis for ascites in a 71-year-old patient who came to our department for abdominal pain and signs of anemization. To our knowledge, no published reports are currently available describing an IAE pseudoaneurysm successfully diagnosed with contrast-enhanced ultrasound.

Contrast-enhanced ultrasound (CEUS) in abdominal intervention

The introduction of ultrasound contrast agents has rendered contrast-enhanced ultrasound (CEUS) a valuable complementary technique to address clinically significant problems. This pictorial review describes the use of CEUS guidance in abdominal intervention and illustrates such application for a range of clinical indications. Clinical application of CEUS discussed include commonly performed abdominal interventional procedures, such as biopsy, drainage, nephrostomy, biliary intervention, abdominal tumor ablation and its subsequent monitoring, and imaging of vascular complications following abdominal intervention. The purpose of this article is to further familiarize readers with the application of CEUS, particularly its specific strength over alternative imaging modalities, in abdominal intervention.

Efficacy of contrast-enhanced ultrasonography in detecting graft rupture sites after abdominal aortic aneurysm repair

Non-anastomotic graft rupture is a rare but critical complication after abdominal aortic aneurysm (AAA) repair. Therefore, identifying the rupture sites is important to perform endovascular stent grafting. A 78-year old man who had undergone Y-grafting for infrarenal AAA before 17 years was referred to our hospital with the complaints of abdominal pain. Computed tomography revealed acute pancreatitis and an enlargement around the grafted abdominal aorta. Contrast-enhanced ultrasonography revealed an extravazation from the graft body 1.5 cm distal to the proximal anastomosis, and endovascular stent grafting was successfully performed. Contrast-enhanced ultrasonography might be useful in detecting the graft rupture.

Real-time 3-dimensional contrast-enhanced ultrasound in detecting hemorrhage of blunt renal trauma

OBJECTIVES

The objective of this study is to evaluate the diagnostic value of real-time 3-dimensional contrast-enhanced ultrasound in the hemorrhage of blunt renal trauma.

METHODS

Eighteen healthy New Zealand white rabbits were randomly divided into 3 groups. Blunt renal trauma was performed on each group by using minitype striker. Ultrasonography, color Doppler flow imaging, and contrast-enhanced 2-dimensional and real-time 3-dimensional ultrasound were applied before and after the strike. The time to shock and blood pressure were subjected to statistical analysis. Then, a comparative study of ultrasound and pathology was carried out.

RESULTS

All the struck kidneys were traumatic. In the ultrasonography, free fluid was found under the renal capsule. In the color Doppler flow imaging, active hemorrhage was not identified. In 2-dimensional contrast-enhanced ultrasound, active hemorrhage of the damaged kidney was characterized. Real-time 3-dimensional contrast-enhanced ultrasound showed a real-time and stereoscopic ongoing bleeding of the injured kidney. The wider the hemorrhage area in 4-dimensional contrast-enhanced ultrasound was, the faster the blood pressure decreased.

CONCLUSIONS

Real-time 3-dimensional contrast-enhanced ultrasound is a promising noninvasive tool for stereoscopically and vividly detecting ongoing hemorrhage of blunt renal trauma in real time.

Liver haemostasis using microbubble-enhanced ultrasound at a low acoustic intensity

OBJECTIVES

To explore the haemostatic effects of microbubble-enhanced ultrasound (MEUS) at a very low acoustic intensity on the bleeding liver of rabbits.

METHODS

Liver incisions made on 20 rabbits were treated with a pulsed therapeutic ultrasound transducer. The transducer was operated at 831 KHz with an acoustic intensity of 0.4 W/cm(2). The treatment was coordinated with intravenous injection of microbubbles. Ultrasound only and sham treatment served as the controls. Visual bleeding score and 10-min bleeding volume were evaluated for haemostatic efficacy. Contrast-enhanced ultrasound (CEUS) was performed to assess the liver perfusion. Nine treated livers were harvested for acute histological examination.

RESULTS

Regarding the bleeding incisions made on rabbit livers, the haemorrhage stopped immediately after 2 min of MEUS treatment but bleeding continued in the controls treated by ultrasound or microbubble injection alone. The bleeding scores and the 10-min haemorrhagic volumes dropped significantly in the MEUS group compared with those of the controls (p < 0.01). The mechanism of MEUS haemostasis appears to involve the extensive swelling of hepatocytes and the haemorrhage of the portal area, which formed a joint compression on the regional liver circulation.

CONCLUSIONS

Low acoustic intensity MEUS might provide a novel method for liver haemostasis.

KEY POINTS

• This animal experiment demonstrates a novel method of controlling hepatic haemorrhage • The treatment uses therapeutic ultrasound during enhancement with intravenous microbubbles • This combined therapy was more effective than ultrasound or intravenous microbubbles alone • More work is required with larger animals before potential human trials.

Focused assessment with sonography for trauma: methods, accuracy, and indications

Focused assessment with sonography for trauma (FAST) is an invaluable adjunct in the management of trauma patients for detection of free intra-abdominal and pericardial fluid. Over the past 2 decades, the use of this technique has increased significantly. This article reviews the clinical application and future direction of FAST.

CEUS in abdominal trauma: multi-center study

The objective of this study was to evaluate the concordance of US and contrast-enhanced US (CEUS) with CT in the assessment of solid organ injury following blunt trauma. Patients underwent complete US examination, including free fluid search and solid organ analysis. CEUS followed, using low-mechanical index techniques and SonoVue. CT was performed within 1 h. Among 156 enrolled patients, 91 had one or more abnormalities (n = 107) at CT: 26 renal, 38 liver, 43 spleen. Sensitivity, specificity, and accuracy for renal trauma at baseline US were 36%, 98%, and 88%, respectively, after CEUS values increased to 69%, 99%, and 94%. For liver baseline US values were 68%, 97%, and 90%; after CEUS were 84%, 99%, and 96%. For spleen, results were 77%, 96%, and 91% at baseline US and 93%, 99%, and 97% after CEUS. Per patient evaluation gave the following results in terms of sensitivity, specificity and accuracy: 79%, 82%, 80% at baseline US; 94%, 89%, and 92% following CEUS. CEUS is more sensitive than US in the detection of solid organ injury, potentially reducing the need for further imaging. False negatives from CEUS are due to minor injuries, without relevant consequences for patient management and prognosis.

Hemostasis of active bleeding from the liver with percutaneous microwave coagulation therapy under contrast-enhanced ultrasonographic guidance: an experimental study

OBJECTIVE

The purpose of this study was to investigate the feasibility of percutaneous microwave coagulation therapy (PMCT) guided by contrast-enhanced ultrasonography (CEUS) for controlling active bleeding in rabbit livers.

METHODS

Twenty actively bleeding rabbit liver models, produced with an 18-gauge semiautomatic biopsy needle and confirmed with CEUS, were randomly divided into 2 groups: a PMCT group (n=10, with a microwave antenna placed into the bleeding site under ultra-sonographic guidance and worked at 60 W for 30 seconds on average) and a control group (n=10, with the active bleeding site not treated). After therapy procedures were performed, lactated Ringer's solution resuscitation was then performed in both groups to maintain the mean arterial pressure at 70 mm Hg for 1 hour. The intraperitoneal blood loss, total resuscitation volume, mean arterial pressure, and hematocrit value were recorded. Macroscopic and microscopic examinations were performed at the end of the study.

RESULTS

After PMCT, the former bleeding site appeared on CEUS as a round or an oval area devoid of contrast. The PMCT group had lower blood loss (30.4+/-7.2 versus 101.6 +/- 18.2 mL; P< .05) and a lower total resuscitation volume (56.5+/-10 versus 186+/-36.6 mL; P< .05) than the control group. The mean hematocrit value in the PMCT group was significantly higher than that in the control group (26%+/-4% versus 19%+/-4%; P< .05) at the end of the experiment.

CONCLUSIONS

Contrast-enhanced ultrasonographically guided PMCT significantly decreased blood loss in a rabbit model of active liver bleeding. It provides a simple and quick method to control blood loss in liver injuries with active bleeding.

The value of contrast-enhanced gray-scale ultrasound in the diagnosis of hepatic trauma: an animal experiment

BACKGROUND

Conventional ultrasonography (US) shows markedly lower sensitivity in detecting parenchymal injury and active bleeding in abdominal organs. This study was designed to evaluate the utility of contrast-enhanced US (CEUS) in the diagnosis of blunt trauma and active hemorrhage of the liver in an animal model.

METHODS

Sixteen blunt injuries and 40 lacerations with active hemorrhage were created in livers of 14 pigs using laparotomy. The lacerations were divided into two groups: group I, in which the velocity of the traumatized artery was >20 cm/s; and group II, in which the velocity of the traumatized artery was < or =20 cm/s. Twenty minutes after the blunt trauma and immediately after the laceration was created, conventional US and CEUS were performed to observe the sonographic characteristics of trauma.

RESULTS

The sensitivity of CEUS in detecting blunt hepatic trauma (100%; 16 of 16) was significantly higher than that of conventional US (37.5%; 6 of 16) (p < 0.001) based on the histopathology gold standard. Active hemorrhage was clearly detected as hyperechoic enhanced linear or clumpy regions in all of the lacerations in group I (100%; 20 of 20) and in 65% (13 of 20) of the lacerations in group II on CEUS. Acoustic shadowing was observed posterior to the enhanced hemorrhagic site in 12 lacerations from group I and in five lacerations from group II.

CONCLUSION

In this animal model, CEUS was found to be useful in detecting blunt trauma and active hemorrhage in the liver, which might significantly improve the efficacy of US for the diagnosis of hepatic trauma.

Hemorrhage control using high intensity focused ultrasound

Hemorrhage control is a high priority task in advanced trauma care, because hemorrhagic shock can result in less than a minute in cases of severe injuries. Hemorrhage was found to be solely responsible for 40-50% of traumatic civilian and battlefield deaths in recent years. The majority of these deaths were due to abdominal and pelvic injuries with hidden and inaccessible bleeding of solid organs such as liver, spleen, and kidneys, as well as major blood vessels. High intensity focused ultrasound (HIFU) offers a promising method for hemorrhage control. An important advantage of HIFU is that it can deliver energy to deep regions of tissue where hemorrhage is occurring, allowing cauterization at depth of parenchymal tissues, or in difficult-to-access anatomical regions, while causing no or minimal biological effects in the intervening and surrounding tissues. Moreover, HIFU can cause both thermal and mechanical effects that are shown to work synergistically for rapid hemorrhage control. The major challenges of this method are in development of bleeding detection techniques for accurate localization of the injury sites, delivery of large HIFU doses for profuse bleeding cases, and ensuring safety when critical structures are in the vicinity of the injury. Future developments of acoustic hemostasis technology are anticipated to be for applications in peripheral vascular injuries where an acoustic window is usually available, and for applications in the operating room on exposed organs.

Image-guided acoustic hemostasis for hemorrhage in the posterior liver

We investigated the use of ultrasound image-guided high intensity focused ultrasound (HIFU) to stop bleeding from injuries in the posterior liver. A HIFU transducer with focal length of 3.5 cm and frequency of 3.2 MHz was integrated with an intraoperative high-resolution ultrasound-imaging probe. Wedge tissue extractions, 30-mm long, 5-mm wide and 8-mm deep, were made in the posterior liver surface of five pigs to induce bleeding. The device was positioned on the anterior surface of the liver and HIFU was applied using ultrasound image-guidance. Hemostasis was achieved in 66 +/- 18 s (mean +/- standard deviation) for 17 HIFU treatments. During 7 min of sham HIFU treatment, none of the control incisions (n = 7) became hemostatic. Ultrasound image-guided HIFU offers a promising method for hemostasis in surgical settings in which the hemorrhage site is hidden and/or not accessible.

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.

Ultrasonic interrogation of tissue vibrations in arterial and organ injuries: preliminary in vivo results

Soft tissues surrounding vascular injuries are known to vibrate at audible and palpable frequencies, producing bruits and thrills. We report the results of a feasibility study where Doppler ultrasound (US) was used to quantitatively estimate the tissue vibrations after induced trauma in an animal model. A software-programmable US system was used to acquire quadrature-demodulated ensembles of received US echoes bypassing clutter filtering and other conventional Doppler processing stages. The waveforms of tissue velocity surrounding the injury site were then estimated from the clutter data using autocorrelation and analyzed to determine vibration characteristics. Six New Zealand white rabbits and two juvenile pigs were used for the study. The femoral artery of the anesthetized animal was punctured with an 18-gauge needle to model a peripheral arterial trauma, and the liver was surgically exposed and incised to model organ trauma. Two types of oscillatory tissue motion were observed: "vibrations" with high frequency (>50 Hz) and low peak-peak amplitude (<1 microm) and "flutter" with low frequency (<50 Hz) and high peak-peak amplitude (>1 microm). Active bleeding in femoral artery punctures produced tissue vibrations at the frequency of 323 +/- 214 Hz (mean +/- standard deviation, pooled for both rabbits and pigs) and the amplitude of 0.24 +/- 0.15 microm. Active bleeding in liver incisions produced vibrations at the frequency of 120 +/- 47 Hz and the amplitude of 0.33 +/- 0.25 microm. Flutter was observed in punctured arteries at the frequency of 28 +/- 13 Hz the amplitude of 2.92 +/- 1.75 microm, and in incised livers at the frequency of 26 +/- 6 Hz and the amplitude of 1.53 +/- 0.76 microm. In a punctured artery, the vibration frequency and phase of tissue surrounding the artery were highly correlated between neighboring locations in tissue (correlation coefficient = 0.98), and with the flow oscillations in the lumen (correlation coefficient = 0.96). This preliminary study indicates that tissue vibrations could provide additional physiologic information for detecting, localizing and monitoring internal bleeding using US.

Active abdominal bleeding: contrast-enhanced sonography

Active contrast medium extravasation is a recognized and important angiographic and computed tomographic (CT) sign of bleeding. It is an indicator of active, ongoing, and potentially life-threatening hemorrhage and, hence, of the need for an immediate surgical or interventional treatment. Sonography (US) is frequently used as the first imaging option for screening patients with traumatic and nontraumatic abdominal emergencies. Owing to the current possibilities of low-mechanical index, real-time, contrast-specific systems, it is now possible to detect a contrast leakage by using US. This finding opens new possibilities in the assessment and management of several abdominal emergencies, including trauma (initial workup and monitoring), spontaneous hematomas, and rupture of aneurysms or masses. This article describes the technique, findings, possibilities, and limitations of contrast-enhanced US in the evaluation of active abdominal bleeding.

Real-time, contrast-enhanced sonography: a new tool for detecting active bleeding

BACKGROUND

Active contrast medium extravasation is a known angiographic and computed tomographic sign of ongoing, potentially life-threatening hemorrhage. Sonography (US) is frequently the first imaging option for screening patients with abdominal emergencies. Because of the current possibilities of low-mechanical-index, real-time, contrast-specific systems, it is possible to detect contrast leakage by using US. The purpose of this article is report our pilot experience in the evaluation of active traumatic and nontraumatic bleeding with contrast-enhanced US.

METHODS

In a 2-year period, we performed 153 consecutive emergent contrast-enhanced US studies. Traumatic emergencies accounted for 83 examinations and nontraumatic emergencies accounted for 70. We used the contrast-specific mode Contrast Tuned Imaging and the contrast medium SonoVue. A 2.4- to 4.8-mL contrast medium bolus was injected with continuous US acquisition, starting immediately after contrast injection and lasting 1 to 6 minutes.

RESULTS

Contrast extravasation was found in 20 cases (13%). These included spleen injury (n = 8), liver injury (n = 3), kidney injury (n = 1), abdominal aortic aneurysm rupture (n = 5), splenic angiosarcoma rupture (n = 1), postsurgical bleeding after abdominal aortic aneurysm repair (n = 1), and postsplenectomy bleeding (n = 1). Active extravasation appeared as a round, hyperechoic pool or as a fountain-like, hyperechoic jet.

CONCLUSION

Our retrospective clinical study shows for the first time how US can detect contrast medium extravasation, a significant indicator of active hemorrhage and of need for prompt surgical or interventional treatment.

Extending the frontiers of surgical therapy for hepatic colorectal metastases: is there a limit?

Hepatic resection for colorectal metastases, limited to the liver, has become the standard of care, and currently remains the only potentially curative therapy. Numerous single institutional reports have demonstrated long-term survival, and there are no other treatment options that have shown a survival plateau. However, curative resection is possible in less than 25% of patients with disease limited to the liver, which consequently translates into only 5% to 10% of the original group developing colorectal cancer. To increase the number of patients who could benefit from hepatic resection, the last decade has seen considerable effort directed towards the following areas, (1) refining prognostic factors that would improve patient selection, (2) advancements in surgical technique such as, use of intraoperative ultrasonography, controlling hemorrhage through use of vascular clamping techniques supplemented with low central venous pressure anesthesia, availability of novel devices for parenchymal transection, and controlled anatomic hepatectomy with Glissonian technique, and (3) novel approaches to permit curative hepatic resection such as, preoperative portal vein embolization for hypertrophy of future liver remnant and staged hepatic resection. This article reviews development of these innovative multidisciplinary modalities and the aggressive surgical approach that has been adopted to extend the frontiers of surgical therapy for colorectal hepatic metastases.

Feasibility of FAST examination performance with ultrasound contrast

The Focused Abdominal Sonography in Trauma (FAST) examination has several limitations, among which is the inability to reliably detect solid organ injury. We sought to evaluate the feasibility of ultrasound contrast use during a FAST examination and its effect on the ability to delineate vasculature in the spleen and liver from hilum to capsule on simulated patients. This prospective observational case control study was conducted at an urban community hospital Emergency Department (ED) that is a level I trauma facility. During a FAST examination, the liver and spleen were scanned in entirety to evaluate contrast opacification of blood vessels and a latent phase highlighting the parenchyma of the liver and spleen. Each physician, hospital credentialed for the use of emergency ultrasound, scanned the liver and spleen both before and after contrast administration. Five milliliters of contrast were mixed with 16 mL of normal saline and then injected 4 mL at a time through an 18-gauge anticubital catheter. All examinations were successfully completed before contrast agent dissipation. The mean time to complete the FAST examination with interrogation of the liver and spleen was 1 min 42 s (range 1 min 22 s to 2 min 5 s). The mean time to initial visualization of contrast was 15 s (range 12 to 18 s). The latent phase of the ultrasound contrast when the liver or spleen began to shimmer, an effect that would outline hematomas not actively bleeding, occurred at a mean time of 54 s (range 45 s to 1 min 9 s). The ultrasound contrast disappeared at a mean of 2 min 52 s (range of 2 min 16 s to 3 min 33 s). In conclusion, ultrasound contrast use is feasible during the FAST examination and allows enhanced evaluation of solid organ parenchyma during evaluation for solid organ injury.

A novel application of ultrasound contrast: demonstration of splenic arterial bleeding

Recent research in the use of ultrasound contrast agents has found they are able to increase the diagnostic power of ultrasound, to a level that may exceed other imaging modalities, in the diagnosis of liver lesions. Their application in the assessment of haemorrhage following angiographic embolisation has not previously been described. We report on a case where metal coil embolisation of a bleeding splenic artery aneurysm was completed to angiographic satisfaction, but on injection of ultrasound contrast medium, the aneurysm, distal to the embolisation, showed the presence of ultrasound contrast medium within it. We suggest that contrast enhanced ultrasound may be more sensitive than conventional angiography in the assessment of blood flow through intra-abdominal small vessel aneurysms or solid organs.

Renal imaging with ultrasound contrast: current status

The application of UCAs to the kidney is still in its infancy; however, there are several areas of great promise. UCAs may replace CT in complex renal cyst evaluation and follow-up, eliminating the need for costly CT scans with their attendant potential contrast nephrotoxicity. This approach may decrease patient and physician uncertainty and improve diagnostic confidence. The use of UCAs is likely to be clinically useful in the evaluation of the indeterminate small renal mass on CT or MR imaging. Another probable useful application will be in renal artery stenosis. Routine application of UCAs may increase the percentage of diagnostic examinations, increase diagnostic confidence, and decrease examination times. It also will likely become the first line of evaluation in pyelonephritis, and be useful in immediate assessment of residual tumor after radiofrequency ablation. Of course, substantial additional work needs to be performed in large groups of patients to prove this currently optimistic outlook.

Contrast enhanced vascular three-dimensional ultrasound imaging

In other imaging modalities three-dimensional (3D) data displays are well established; not so in ultrasound. Due to the real-time requirements of ultrasound the time available to compute 3D displays is limited, particularly when flow data is acquired with Doppler techniques. Consequently, it is only recently that improvements in computer processing power have resulted in useful vascular 3D ultrasound scans. Many manufacturers have now implemented free-hand 3D power Doppler capabilities on their scanners. However, to obtain flow signals from smaller vessels associated e.g., with tumor neovascularity, may very well require the introduction of a microbubble based ultrasound contrast agent into the blood stream. Given the up to 30 dB enhancement of Doppler signals produced by the contrast microbubbles quite spectacular vascular 3D images are feasible. Moreover, new contrast imaging techniques, such as harmonic imaging, have now permitted 3D vascular information to be acquired and displayed in grayscale with the associated improvement in resolution. In this paper we will review different aspects of contrast enhanced vascular 3D ultrasound imaging including implementation, contrast specific techniques and in vivo imaging.