Role of Ultrasound in the Management of Ovarian Carcinoma

The ultrasound findings of the pelvis, upper abdomen and peritoneal cavity were correlated with second-look laparotomy in 85 patients with Stage III or Stage IV ovarian carcinoma. High values of accuracy were obtained for the pelvis (90%) and liver (91%) but ultrasound was insensitive to peritoneal disease unless ascites was present.

Microflow imaging: New Doppler technology to detect low-grade inflammation in patients with arthritis

Aim

To assess the efficacy of microvascular imaging in detecting low-grade inflammation in arthritis compared with Power Doppler ultrasound (PDUS).

Method and materials

Patients presenting for ultrasound with arthralgia were assessed with grey-scale, PDUS and Superb Microvascular Imaging (SMI). Videoclips were stored for analysis at a later date. Three musculoskeletal radiologists scored grey-scale changes, signal on PDUS and/or SMI within these joints. If a signal was detected on both PDUS and SMI, the readers graded the conspicuity of vascular signal from the two Doppler techniques using a visual analogue scale.

Results

Eighty-three patients were recruited with 134 small joints assessed. Eighty-nine of these demonstrated vascular flow with both PD and SMI, whilst in five no flow was detected. In 40 joints, vascularity was detected with SMI but not with PDUS (p = 0.007). Out of the 89 joints with vascularity on both SMI and PDUS, 23 were rated as being equal; while SMI scored moderately or markedly better in 45 cases (p <0.001).

Conclusion

SMI is a new Doppler technique that increases conspicuity of Doppler vascularity in symptomatic joints when compared to PDUS. This allows detection of low grade inflammation not visualised with Power Doppler in patients with arthritis.

Key Points

• SMI detects vascularity with improved resolution and sensitivity compared to Power Doppler.

• SMI can detect low-grade inflammation not seen with Power Doppler.

• Earlier detection of active inflammation could have significant impact on treatment paradigms.

Electronic supplementary material

The online version of this article (doi:10.1007/s00330-017-5016-4) contains supplementary material, which is available to authorized users.

Guidelines and good clinical practice recommendations for contrast enhanced ultrasound (CEUS) in the liver--update 2012: a WFUMB-EFSUMB initiative in cooperation with representatives of AFSUMB, AIUM, ASUM, FLAUS and ICUS

Initially, a set of guidelines for the use of ultrasound contrast agents was published in 2004 dealing only with liver applications. A second edition of the guidelines in 2008 reflected changes in the available contrast agents and updated the guidelines for the liver, as well as implementing some non-liver applications. Time has moved on, and the need for international guidelines on the use of CEUS in the liver has become apparent. The present document describes the third iteration of recommendations for the hepatic use of contrast enhanced ultrasound (CEUS) using contrast specific imaging techniques. This joint WFUMB-EFSUMB initiative has implicated experts from major leading ultrasound societies worldwide. These liver CEUS guidelines are simultaneously published in the official journals of both organizing federations (i.e., Ultrasound in Medicine and Biology for WFUMB and Ultraschall in der Medizin/European Journal of Ultrasound for EFSUMB). These guidelines and recommendations provide general advice on the use of all currently clinically available ultrasound contrast agents (UCA). They are intended to create standard protocols for the use and administration of UCA in liver applications on an international basis and improve the management of patients worldwide.

A comparison of 31P magnetic resonance spectroscopy and microbubble-enhanced ultrasound for characterizing hepatitis c-related liver disease

We compared in vivo hepatic (31) P magnetic resonance spectroscopy ((31) P MRS) and hepatic vein transit times (HVTT) using contrast-enhanced ultrasound with a microbubble agent to assess the severity of hepatitis C virus (HCV)-related liver disease. Forty-six patients with biopsy-proven HCV-related liver disease and nine healthy volunteers had (31) P MRS and HVTT performed on the same day. (31) P MR spectra were obtained at 1.5 T. Peak areas were calculated for metabolites, including phosphomonoesters (PME) and phosphodiesters (PDE). Patients also had the microbubble ultrasound contrast agent, Levovist (2 g), injected into an antecubital vein, and time-intensity Doppler ultrasound signals of the right and middle hepatic veins were measured. The HVTT was calculated as the time from injection to a sustained rise in Doppler signal 10% greater than baseline. The shortest times were used for analysis. Based on Ishak histological scoring, there were 15 patients with mild hepatitis, 20 with moderate/severe hepatitis and 11 with cirrhosis. With increasing severity of disease, the PME/PDE ratio was steadily elevated, while the HVTT showed a monotonic decrease. Both imaging modalities could separate patients with cirrhosis from the mild and moderate/severe hepatitis groups. No statistical difference was observed in the accuracy of each test to denote mild, moderate/severe hepatitis and cirrhosis (Fisher's exact test P =1.00). (31) P MRS and HVTT show much promise as noninvasive imaging tests for assessing the severity of chronic liver disease. Both are equally effective and highly sensitive in detecting cirrhosis.

Quantitative contrast-enhanced ultrasound imaging: a review of sources of variability

Ultrasound provides a valuable tool for medical diagnosis offering real-time imaging with excellent spatial resolution and low cost. The advent of microbubble contrast agents has provided the additional ability to obtain essential quantitative information relating to tissue vascularity, tissue perfusion and even endothelial wall function. This technique has shown great promise for diagnosis and monitoring in a wide range of clinical conditions such as cardiovascular diseases and cancer, with considerable potential benefits in terms of patient care. A key challenge of this technique, however, is the existence of significant variations in the imaging results, and the lack of understanding regarding their origin. The aim of this paper is to review the potential sources of variability in the quantification of tissue perfusion based on microbubble contrast-enhanced ultrasound images. These are divided into the following three categories: (i) factors relating to the scanner setting, which include transmission power, transmission focal depth, dynamic range, signal gain and transmission frequency, (ii) factors relating to the patient, which include body physical differences, physiological interaction of body with bubbles, propagation and attenuation through tissue, and tissue motion, and (iii) factors relating to the microbubbles, which include the type of bubbles and their stability, preparation and injection and dosage. It has been shown that the factors in all the three categories can significantly affect the imaging results and contribute to the variations observed. How these factors influence quantitative imaging is explained and possible methods for reducing such variations are discussed.

Hepatic vein transit times of a microbubble agent in assessing response to antiviral treatment in patients with chronic hepatitis C

Microbubble measurement of hepatic vein transit times (HVTT) may have the potential to assess severity of hepatitis C virus (HCV)-related liver disease, where there is a shorter HVTT with more severe disease. We investigated the utility of this test as a marker of response to antiviral treatment. Thirty-seven patients with biopsy-proven HCV-related disease undergoing antiviral treatment were studied. All had baseline scans and then repeat scans 6 months after the end of treatment. HVTT using Levovist were obtained from the right and middle hepatic veins, and the shorter time was used for analysis. The aspartate aminotransferase to platelet ratio index (APRI) scores were calculated retrospectively. There were seven patients with mild hepatitis, 23 with moderate/severe hepatitis and seven with cirrhosis. The mean baseline HVTT in responders ± SE increased from 27.3 ± 2.29 s to 33.5 ± 2.8 s posttreatment (P = 0.01). In the 10 nonresponders, the HVTT remained the same; 43.3 ± 9 s baseline compared to 44 ± 7.8 s posttreatment (P = 0.84). This trend was also seen with the APRI score where in responders, the mean score decreased from 1.1 ± 0.2 to 0.74 ± 1 (P = 0.03) and in nonresponders, the score remained unchanged; 0.88 ± 0.2 compared to 0.84 ± 0.2 (P = 0.31). HVTT measurement lengthened, while APRI scores decreased in patients who responded to antiviral treatment while both remained the same, shortened (HVTT) or increased (APRI), respectively, in patients who were nonresponders. These results are encouraging and indicate that these tests could be potentially used as markers of response to treatment and could obviate the need for serial biopsies in antiviral future treatment studies.

Can contrast-enhanced sonography distinguish benign from malignant breast masses?

BACKGROUND

We investigated whether microvascular enhancement on contrast-enhanced sonographic (CEUS) imaging can aid in distinguishing between benign and malignant lesions and correlated these findings with histopathological findings.

METHOD

Fifteen patients with a palpable breast mass were recruited. Following informed consent, 4.8 mL of the microbubble contrast agent SonoVue was injected intravenously. Digital video clips of lesion enhancement were obtained and reviewed by a consultant radiologist who scored each lesion on the following characteristics: homogeneous versus heterogeneous enhancement, the presence or absence of focal defects, well- versus ill-defined margins and vascular morphology score (VMS).

RESULT

Histologically there were 7 malignant and 8 benign lesions. The calculated sensitivity for CEUS in the diagnosis of malignancy was 100%, with a 37.5% specificity. There was no statistically significant difference in overall mean VMS between the malignant and benign lesions.

CONCLUSION

The results of our study have not shown any additional benefit in the use of CEUS over conventional triple assessment. The positive trend seen in the higher mean VMS for the malignant tumors needs further investigation with a larger cohort of patients.

Can contrast-enhanced ultrasonography characterize focal liver lesions and differentiate between benign and malignant, thus providing a one-stop imaging service for patients?()

PURPOSE

Contrast-enhanced ultrasonography (CEUS) displays high sensitivity and specificity in characterizing focal liver lesions (FLLs). We attempted to determine how often CEUS provides an unequivocal diagnosis of FLLs that does not require additional imaging studies.

MATERIALS AND METHODS

Seventy-three patients with 146 FLLs were scanned with B-mode, Doppler, and contrast-enhanced US (2 × 2.4 ml SonoVue, low MI, 4-6 MHz curved array transducer, Toshiba Aplio/Siemens-Acuson Sequoia). Data were digitally stored and transferred to a work station with the GE PACS system. Images were reviewed by a consultant radiologist experienced in CEUS and interpreted in accordance with the criteria for characterizing FLLs published by the European Federation of Societies for Ultrasound in Medicine and Biology. Diagnoses were compared with those based on computed tomography (CT) and/or magnetic resonance (MR) findings if these were available. However, our aim was to assess the frequency with which CEUS provided diagnoses that were considered reliable enough to exclude the need for other imaging studies. Therefore, the CEUS diagnoses were not necessarily confirmed by other methods.

RESULTS

Based on CEUS findings alone, 130/146 (89.0%) FLLs could be classified as benign or malignant, and in 118/146 (80.8%) cases, the lesion could be specifically identified. The other 28/146 (19.2%) FLLs could not be characterized based on CEUS data alone. In 58 (80.8%) of the 73 patients with multiple FLLs, CEUS findings were sufficient to establish the benign vs. malignant nature of all the patient's lesions; in 51/73 (69.9%) patients, all the lesions could also be characterized with CEUS. In the remaining cases, at least one lesion required additional imaging to determine whether it was malignant (14/73, 19.2%) or to establish its identity (22/73, 30.1%). In 4/73 (5.5%) patients, CEUS revealed additional lesions not detected on B-mode US.

CONCLUSIONS

CEUS alone was sufficient to classify 89.0% of the FLLs as benign or malignant, and in 80.8% it was also regarded as sufficient to identify the lesion. It served as a one-stop diagnostic test for 80.8% of the patients, reducing the need for CT-MR scans and providing savings in terms of radiation exposure, time, and money.

Ultrasonographic and radiographic results from a two-year controlled trial of immediate or one-year-delayed addition of infliximab to ongoing methotrexate therapy in patients with erosive early rheumatoid arthritis

OBJECTIVE

To compare the impact of immediate and delayed introduction of anti-tumor necrosis factor therapy on inflammation and structural damage in methotrexate (MTX)-treated patients with early rheumatoid arthritis (RA).

METHODS

Twenty-four patients with erosive early RA (duration < 3 years) who were receiving MTX were randomized to receive infliximab 5 mg/kg or placebo infusions at weeks 0, 2, and 6, and then every 8 weeks through week 46. Beginning at week 54 and thereafter, all patients received infliximab 5 mg/kg. Metacarpophalangeal joints were scanned using high-frequency ultrasonography and power Doppler imaging. Radiographs were evaluated using the modified Sharp/van der Heijde scoring system.

RESULTS

From baseline to week 54, total synovial thickness was significantly improved in the infliximab + MTX group compared with the placebo + MTX group (median reduction 95.8% versus 37.5%; P = 0.005), as was the total color Doppler area (CDA; vascularity assessment) (median reduction 100% and 47.1%, respectively; P = 0.025). From week 0 to week 110, no significant between-group difference was observed in the change from baseline for total synovial thickening or the total CDA. At week 54, greater progression in the Sharp/van der Heijde score was apparent in patients receiving placebo + MTX compared with those receiving infliximab + MTX. Although radiographic progression in the placebo + MTX group was greatly reduced in the second year (after initiation of infliximab therapy), marked differences were observed between the infliximab + MTX group (median change in the Sharp/van der Heijde score 4.0) and the placebo + MTX group (median change 14.5) from baseline to week 110 (P = 0.076).

CONCLUSION

The results indicate that the efficacy of 2 years of combination therapy with infliximab + MTX for inhibiting cumulative structural damage was superior to that of 1 year of treatment with MTX alone followed by the addition of infliximab.

Diagnostic efficacy of SonoVue®, a second generation contrast agent, in the assessment of extracranial carotid or peripheral arteries using colour and spectral Doppler ultrasound: a multicentre study

The purpose of this study was to demonstrate the improvement in diagnostic quality and diagnostic accuracy of SonoVue microbubble contrast-enhanced ultrasound (CE-US) versus unenhanced ultrasound imaging during the investigation of extracranial carotid or peripheral arteries. 82 patients with suspected extracranial carotid or peripheral arterial disease received four SonoVue doses (0.3 ml, 0.6 ml, 1.2 ml and 2.4 ml) with Doppler ultrasound performed before and following each dose. Diagnostic quality of the CE-US examinations was evaluated off-site for duration of clinically useful contrast enhancement, artefact effects and percentage of examinations converted from non-diagnostic to diagnostic. Accuracy, sensitivity and specificity were assessed as agreement of CE-US diagnosis evaluated by an independent panel of experts with reference standard modality. The median duration of clinically useful signal enhancement significantly increased with increasing SonoVue doses (p< or =0.002). At the dose of 2.4 ml of SonoVue, diagnostic quality evaluated as number of inconclusive examinations significantly improved, falling from 40.7% at baseline down to 5.1%. Furthermore, SonoVue significantly (p<0.01) increased the accuracy, sensitivity and specificity of assessment of disease compared with baseline ultrasound. SonoVue increases the diagnostic quality of Doppler images and improves the accuracy of both spectral and colour Doppler examinations of extracranial carotid or peripheral arterial disease.

Hepatic vein transit times using a microbubble agent can predict disease severity non-invasively in patients with hepatitis C

BACKGROUND AND AIMS

A reliable non-invasive assessment of the severity of diffuse liver disease is much needed. We investigated the utility of hepatic vein transit times (HVTT) for grading and staging diffuse liver disease in a cohort of patients with hepatitis C virus (HCV) infection using an ultrasound microbubble contrast agent as a tracer.

MATERIALS AND METHODS

Eighty five untreated patients with biopsy proven HCV induced liver disease were studied prospectively. All were HCV RNA positive on polymerase chain reaction testing. Based on their histological fibrosis (F) and necroinflammatory (NI) scores, untreated patients were divided into mild hepatitis (F < or =2/6, NI < or =3/18), moderate/severe hepatitis (3 < or =F <6 or NI > or =4), and cirrhosis (F=6/6) groups. In addition, 20 age matched healthy volunteers were studied. After an overnight fast, a bolus of contrast agent (Levovist) was injected into an antecubital vein and spectral Doppler signals were recorded from both the right and middle hepatic veins for analysis. HVTTs were calculated as the time from injection to a sustained rise in Doppler signal >10% above baseline. The Doppler signals from the carotid artery were also measured in 60 patients and carotid delay times (CDT) calculated as the difference between carotid and hepatic vein arrival times. The earliest HVTT in each patient was used for analysis.

RESULTS

Mean (SEM) HVTT for the control, mild hepatitis, moderate/severe hepatitis, and cirrhosis groups showed a monotonic decrease of 38.1 (2.8), 38.8 (2.4), 26.0 (2.4), and 15.8 (0.8) seconds, respectively. Mean (SEM) CDT for the control, mild hepatitis, moderate/severe hepatitis, and cirrhosis patients again showed progressive shortening of 30.3 (2.6), 25.9 (2.6), 14.8 (2.1), and 5.6 (1.2) seconds, respectively. There were significant differences between the groups for HVTT (ANOVA, p<0.001) and CDT (ANOVA, p<0.001). There was 100% sensitivity and 80% specificity for diagnosing cirrhosis and 95% sensitivity and 86% specificity for differentiating mild hepatitis from more severe liver disease.

CONCLUSION

We have shown, for the first time, that HVTT using an ultrasound microbubble contrast agent can assess HCV related liver disease with clear differentiation between mild hepatitis and cirrhosis. There were significant differences between these two groups and the moderate/severe hepatitis group. CDT offers no additional benefit or greater differentiation than HVTT and can be omitted, thus simplifying this technique. HVTT may complement liver biopsy and may also be a useful alternative for assessment of liver disease in patients who have contraindications to biopsy.

Ovarian cancer detected non-invasively by contrast-enhanced power Doppler ultrasound

Overall, about one-third of women operated upon because of suspected ovarian cancer turn out to have benign disease. This proportion will be even higher when the tumours are small. A more accurate method of determining which are malignant would reduce the number of unnecessary referrals to the cancer centre and increase the scope for conservative management. This pilot study of ultrasound and intravenous microbubble contrast in 20 women with small ovarian tumours enabled the identification of all four malignant lesions with good inter-observer agreement. These preliminary findings suggest that intravenous contrast improves the ultrasound identification of small ovarian malignancies and may provide an accurate way of selecting women who require to be referred urgently for surgery under the auspices of a gynaecological oncologist. The remainder might be considered for laparoscopic surgery or even for observation in some cases.

Comparison of ultrasonographic assessment of synovitis and joint vascularity with radiographic evaluation in a randomized, placebo-controlled study of infliximab therapy in early rheumatoid arthritis

OBJECTIVE

To investigate sensitive ultrasonographic imaging methods for detection of synovial thickness and vascularity to discriminate between patients with early rheumatoid arthritis (RA) receiving infliximab + methotrexate (MTX) versus placebo + MTX over 18 weeks, and to compare the relationship between synovial thickening and vascularity at baseline and radiologic damage to joints of the hands and feet at 54 weeks.

METHODS

Patients with early RA (duration <3 years) receiving stable dosages of MTX were randomly assigned to receive blinded infusions of 5 mg/kg infliximab (n = 12) or placebo (n = 12) at weeks 0, 2, 6, and then every 8 weeks until week 46. At baseline and week 18, clinical assessments were performed, and metacarpophalangeal joints were assessed by high-frequency ultrasonography and power Doppler ultrasonography measurements. Radiographs of the hands and feet taken at baseline and at 54 weeks were evaluated using the van der Heijde modification of the Sharp method (vdH-Sharp score).

RESULTS

Using changes in the total vdH-Sharp score over 54 weeks and changes in synovial thickening and joint vascularity at 18 weeks, we were able to distinguish those patients receiving infusions of infliximab + MTX from those receiving placebo + MTX. Sonographic measurements of synovial thickening and vascularity at baseline in the placebo + MTX group demonstrated clear relationships with the magnitude of radiologic joint damage at week 54. Infliximab + MTX treatment abolished these relationships.

CONCLUSION

The delay or reversal of inflammatory and joint-destructive mechanisms in patients with early RA was already apparent following 18 weeks of treatment with infliximab + MTX and was reflected in radiologic changes at 54 weeks.

Liver microbubble transit time compared with histology and Child-Pugh score in diffuse liver disease: a cross sectional study

BACKGROUND

A previous pilot study showed that early arrival time of a microbubble in a hepatic vein is a sensitive indicator of cirrhosis.

AIM

To see if this index can also grade diffuse liver disease.

PATIENTS

Thirty nine fasted patients with histologically characterised disease were studied prospectively. Nine patients had no evidence of liver fibrosis, 10 had fibrosis without cirrhosis, and 20 had cirrhosis (five Child's A, seven Child's B, and eight Child's C).

METHODS

Bolus injections of a microbubble (Levovist; Schering, Berlin) were given intravenously, followed by a saline flush. Time intensity curves of hepatic vein and carotid artery spectral Doppler signals were analysed. Hepatic vein transit time (HVTT) was calculated as the time after injection at which a sustained signal increase >10% of baseline was seen. Carotid delay time (CDT) was calculated as the difference between carotid and hepatic vein enhancement.

RESULTS

Diagnostic studies were achieved in 38/39 subjects. Both HVTT and CDT became consistently shorter with worsening disease, as follows (means (SD)): HVTT: no fibrosis 44 (25) s, fibrosis 26 (8) s, Child's A 21 (1) s, Child's B 16 (3) s, and Child's C 16 (2) s; CDT: no fibrosis 31 (29) s, fibrosis 14 (6) s, Child's A 8 (1) s, Child's B 4 (4) s, and Child's C 3 (3) s. These differences were highly significant (p<0.001, ANOVA comparison). A HVTT <24 s and a CDT <10 s were 100% sensitive for cirrhosis (20/20 and 18/18, respectively) but not completely specific: 2/8 subjects with fibrosis had CDT values <10 s and 3/9 had HVTT <24 s.

CONCLUSION

This minimally invasive test shows promise not only in diagnosing cirrhosis but also in assessing disease severity.

Developments in ultrasound contrast media

Ultrasound microbubble contrast agents are effective and safe echo enhancers. An ingenious array of methods are employed to achieve stability and provide a clinically useful enhancement period. Microbubbles enhance ultrasound signals by up to 25 dB (greater than 300-fold increase) due to resonant behaviour. This is used to rescue failed Doppler studies and may be extended to image the microcirculation of tumours and the myocardium using non-linear modes. Functional studies open up a whole range of applications by using a variety of active and passive quantitation techniques to derive indices from the transit of contrast through a tissue of interest. This has been especially successful in the detection of liver metastases and cirrhosis and shows great promise as a clinical tool. It also has great potential in measuring microcirculatory flow velocity. The demonstration that some microbubbles are not just pure blood pool agents but have a hepatosplenic specific phase has extended the versatility of ultrasound. Imaging of this stationary phase with non-linear modes such as phase inversion and stimulated acoustic emission, has improved the sensitivity and specificity of ultrasound in the detection and characterisation of focal liver lesions to rival that of CT and MR.

Development of three-dimensional power Doppler ultrasound imaging of fetoplacental vasculature

To develop an off-line system for three-dimensional (3-D) ultrasound (US) reconstruction of fetoplacental vasculature using colour segmentation and reconstruction software and to determine sources of error in fully freehand ultrasound image acquisition. US images were acquired freehand with the Acuson Sequoia (5C 2-MHz transducer) using power Doppler. After digital transfer to a personal computer, CQ Analysis software (Kinetic Imaging Ltd, Liverpool, UK) was used to segment the colour information from these images, and the resulting 8-bit grey-scale images were used for 3-D rendering using commercial software (VoxBlast, Vaytek Inc., Fairfield, IA, USA). 2-D scanning, software and freehand acquisition accuracy were assessed using a linear test rig and distance and volume phantoms (Dansk Phantom Service Ltd); 2-D scanning accuracy was within 1.3%, and software reconstruction accuracy within 1% for x and y planes and up to 3% for the z plane. Fully freehand acquisition was associated with a 12% to 18% mean percentage error in distance measurement in the plane of acquisition. Volumetric reconstruction inaccuracy was between 1.5% and 19.7% for precisely separated images and between 16.2% and 39.2% for fully freehand image acquisition. Rendered 3-D US vascular images clearly delineated vascular anatomy within the placenta and cord. Fully freehand 3-D US does have a role in off-line reconstruction of vascular anatomy, although variability in the z plane precludes its use for volumetric measurement. (E-mail: a.welsh@ic.ac.uk)

Do different types of liver lesions differ in their uptake of the microbubble contrast agent SH U 508A in the late liver phase? Early experience

PURPOSE

To compare the uptake of SH U 508A in different types of liver lesions by using stimulated acoustic emission.

MATERIALS AND METHODS

Thirty-seven patients with characterized lesions (metastasis, n = 17; hepatocellular carcinoma, n = 4; hemangioma, n = 9; focal nodular hyperplasia, n = 7) received 2.5 g SH U 508A. After 5 minutes, stimulated acoustic emission was elicited by using a previously described method. Liver and/or lesional differences were assessed with videodensitometry (objective conspicuity score), and two observers assessed each lesion by using a six-point scale (subjective conspicuity score).

RESULTS

Metastases and hepatocellular carcinoma had low stimulated acoustic emission; median objective conspicuity scores were 70% and 68% (all scores were > or =43%), respectively, and subjective conspicuity scores were 2 or higher for both observers. Hemangiomas had reduced stimulated acoustic emission, with more variability; the median objective conspicuity score was 41% (range, 9%-72%), and the median subjective conspicuity scores were 2 (range, 1-4) and 3.5 (range, 1-5) for observers 1 and 2, respectively. Focal nodular hyperplasia had stimulated acoustic emission comparable to that of the liver in all cases; the median objective conspicuity score was -4.7% (all scores were <6%), and the subjective conspicuity score was 1 or lower for both observers. This finding completely separated focal nodular hyperplasia and malignancies. Significant differences were seen between focal nodular hyperplasia and all other lesion types (P < .05).

CONCLUSION

Strong late-phase lesional uptake of SH U 508A is characteristic of focal nodular hyperplasia, is seen in some hemangiomas, and was not observed in malignancies.

[Comparison of bolus and infusion of the ultrasound contrast media levovist for color doppler ultrasound of renal arteries]

PURPOSE

To investigate if the duration of Doppler enhancement of the ultrasound contrast agent Levovist can be prolonged by continuous infusion compared to bolus injections in patients.

METHODS

12 patients with suspected renal artery stenosis were included. Each patient received 1 or 2 bolus injections of 4 g each and a "fast" infusion of 3 ml/min (average dose: 7 g) of Levovist. In 8 patients an additional "slow" infusion of 1 ml/min (average dose 4.2 g) was given. The duration of "strong" Doppler signal enhancement and the visualization of vessels were compared.

RESULTS

The duration of strong enhancement was substantially prolonged by the slow infusion (bolus 6:21 min, fast infusion: 8:57 min, slow infusion: 15:12 min, p < 0.001). The dose effectiveness (duration of strong enhancement per 1 g Levovist) was markedly improved from 0:57 min (bolus) to 3:36 min (slow infusion). Visualisation of the renal arteries was more complete with the slow infusion.

CONCLUSION

Levovist infusions at 1 ml/min are superior to bolus injections in the assessment of renal arteries. They prolong the enhancement, make more efficient use of a given dose of contrast material and thus allow additional clinically relevant information to be obtained at reduced cost.

Hepatic malignancies: improved detection with pulse-inversion US in late phase of enhancement with SH U 508A-early experience

Twenty consecutive patients with known liver malignancies underwent ultrasonography (US) in conventional B mode and in pulse-inversion mode in the late hepatic-specific parenchymal phase after intravenous administration of SH U 508A, a microbubble US contrast agent. Two experienced readers assessed subjective and objective conspicuity, number of lesions, and smallest lesion diameter in each mode. Subjective and objective conspicuity were improved with pulse-inversion mode, and smaller lesions were depicted with pulse-inversion mode than with conventional B mode, improving the detection of metastases less than 1 cm in size.

Liver lesions: intermittent second-harmonic gray-scale US can increase conspicuity with microbubble contrast material-early experience

The authors investigated the effect of intermittent second-harmonic gray-scale (ISHGS) ultrasonography (US) with SH U 508A microbubbles on the conspicuity of focal liver lesions. Twenty-three patients were included in the study. Images were analyzed subjectively and quantitatively. Objective lesion conspicuity was increased. In 12 of the 15 patients with liver malignancy, gray-scale defects were seen in previously unsuspected areas. ISHGS US may improve the sensitivity of US for liver lesions.

Sonography of palpable breast cancer

PURPOSE

Because of the increasing use of sonography to rule out cancer in women with palpable breast abnormalities, this study was performed to determine the rate of sonographically occult malignancy in this clinical setting.

METHODS

Women who were recommended for biopsy based on mammographic and/or clinical findings underwent breast sonography. This study retrospectively analyzed the subset of patients with palpable malignant lesions. Lesions were classified as visible or occult on mammography and sonography. Patients without a tissue diagnosis of tumor were excluded.

RESULTS

Of 1,346 masses that underwent biopsy or aspiration, 616 lesions were palpable, and of these, 293 were malignant. Sonography detected all 293 palpable malignant lesions (95% confidence interval for sensitivity, 99-100%). Eighteen lesions were mammographically occult. The median lesion size as determined by sonography was 1.8 cm; for the lesions that were mammographically occult, the median size was 1.6 cm. The most common histopathologic diagnosis for both groups of lesions was infiltrating ductal carcinoma.

CONCLUSIONS

All palpable malignant breast lesions were visible by sonography in patients in whom a biopsy was recommended. However, we caution that until the false-negative rate of sonography for equivocal palpable abnormalities is determined prospectively, sonography cannot be accurately applied to rule out malignancy in this setting.

Ex vivo delineation of placental angioarchitecture with the microbubble contrast agent Levovist

OBJECTIVE

The aim of this study was to delineate placental vasculature with the microbubble contrast agent Levovist (99.9% galactose and 0.1% palmitic acid; Schering AG, Berlin, Germany), with the ultimate goal of delineating placental vascular anatomy in utero.

STUDY DESIGN

A placental lobule from each of 11 term human placentas was perfused on the fetal side of the circulation under physiologic conditions. Randomly assigned dose-concentration combinations of Levovist were administered through a chorionic artery into the corresponding placental lobule, and the resultant echoenhancement with power Doppler imaging was recorded for digital analysis. Interplacental variability was corrected for by averaging the results of three injections at each dose-concentration combination.

RESULTS

Echoenhancement was seen at all dose-concentration combinations in the injected lobule but not in adjacent control lobules. The three dose-concentration combinations that achieved optimal maximal integrated intensity and duration of action for both chorionic vessel and villus enhancement were 100 microL/kg of 400-mg/mL Levovist, 200 microL/kg of 400-mg/mL Levovist, and 400 microL/kg of 200-mg/mL Levovist.

CONCLUSION

Microbubble contrast injection into the fetal vasculature enabled power Doppler imaging echoenhancement both in chorionic vessels and within the villus tree. We speculate that fetal injection of contrast agent may be applied to the delineation of placental lesions or areas of interfetal transfusion, although its applicability will be hindered by the need for fetal blood sampling.

Pulse-inversion mode imaging of liver specific microbubbles: improved detection of subcentimetre metastases

Pulse-inversion mode (a new ultrasound mode) can be used to image the late liver-specific parenchymal phase of the microbubble contrast-agent Levovist. Scanning in pulse-inversion mode after Levovist improves the detection of liver metastases and reveals more lesions of smaller size than conventional ultrasonography and computed tomography.

Twin fetuses: intravascular microbubble US contrast agent administration--early experience

PURPOSE

To explore the feasibility of administering SH U 508A by using a single-needle procedure at ultrasonography (US) in twin pregnancies to confirm interfetal transfusion in monochorionic twins and delineate placental angioarchitecture in pregnancies with twin-twin transfusion syndrome.

MATERIALS AND METHODS

Fourteen twin pregnancies were studied over 12 months: seven with monochorionic twins, including six with twin-twin transfusion syndrome; two of unknown chorionicity; and five with known dichorionic twins discordant for fetal karyotype or anomaly and undergoing selective feticide in the third trimester. Bolus injection of 100 microL/kg of estimated fetoplacental weight of 400 mg/mL of SH U 508A was performed in the intrahepatic vein of one twin, and evidence of interfetal transfusion was sought by means of digital analysis of power Doppler signals in the contralateral twin.

RESULTS

Contralateral twin echo enhancement was seen in four of the nine ultimately histopathologically proved monochorionic twins. As expected, no evidence of echo enhancement in the contralateral twin was seen in any of the five dichorionic twin pregnancies. There was no evidence of fetal compromise associated with the procedure.

CONCLUSION

These pilot results suggest that microbubbles can be used to demonstrate interfetal transfusion but not to delineate placental vascular anatomy.

[Stimulated acoustic emissions with the ultrasound contrast medium levovist: a clinically useful contrast effect with liver-specific properties]

PURPOSE

The purpose of this study was systematically to investigate stimulated acoustic emission (SAE) with the microbubble contrast agent Levovist (Schering AG, Berlin) in vivo with regards to reproducibility, distribution in various organs over time, dependence on technical factors, and influence on the delineation of focal liver lesions.

PATIENTS AND METHODS

2 intravenous injections of 1 g of Levovist were given to 2 dogs and 1-6 injections of 2.5 g Levovist to 5 healthy volunteers and 37 patients. The liver, spleen, large abdominal vessels, and kidney were intermittently scanned for up to 30 min. Studies were evaluated for the presence of SAE signals by 2 observers. In 20 patients with focal liver lesions (15 with metastases, 4 haemangiomata, 1 hepatocellular carcinoma, and 1 cyst) the influence on lesion visualization was also assessed.

RESULTS

SAE effects, lasting up to 30 minutes, were seen in all subjects in the liver and spleen. Vascular and renal SAE signals were noted shortly after injection, lasting up to 6 minutes. SAE was absent or markedly reduced in focal liver lesions, which were seen as colour voids. This increased the conspicuity of focal lesions, and in 5 patients additional metastases were detected that could not be delineated on B-mode alone.

CONCLUSION

A liver- and spleen-specific late phase of Levovist can be consistently demonstrated using SAE and the effect increases the conspicuity of focal liver lesions.

Stimulated acoustic emission to image a late liver and spleen-specific phase of Levovist in normal volunteers and patients with and without liver disease

Quantitative studies were performed to investigate liver- specific uptake of the microbubble Levovist, using stimulated acoustic emission (SAE), which can detect microbubbles even when stationary or slow-moving. These comprised studies of biodistribution comparing the liver and kidney in five normal volunteers, reproducibility in 34 patients, comparison between cirrhotics and controls (n = 9 each) and maximal depth of effect at different frequencies (180 measurements in 31 patients). Stimulated acoustic emission lasted beyond 30 min, with strongly liver-specific properties in each volunteer and was highly reproducible. No difference in the amount of SAE in the superficial liver was seen between cirrhotic and normal livers, but attenuation was higher in cirrhotics. This demonstrates a frequency-dependent effect on liver SAE penetration. We conclude that the liver uptake of Levovist lasts over 30 min, is reproducible, occurs even where diffuse liver disease is present and can be used to assess tissue attenuation in a novel fashion.

Non-invasive diagnosis of hepatic cirrhosis by transit-time analysis of an ultrasound contrast agent

BACKGROUND

Hepatic cirrhosis is accompanied by several haemodynamic changes including arterialisation of the liver, intrahepatic shunts, pulmonary arteriovenous shunts, and a hyperdynamic circulatory state. We postulated that the hepatic first pass of a bolus of an ultrasound contrast agent injected into a peripheral vein is accelerated in patients with cirrhosis. We investigated this first pass in patients with diffuse liver disease and in normal controls to assess whether it provides useful differential diagnostic information.

METHODS

We enrolled 15 patients with biopsy-proven cirrhosis, 12 patients with biopsy-proven non-cirrhotic diffuse liver disease, and 11 normal controls. We carried out continuous spectral doppler ultrasonography of a hepatic vein from 20 s before to 3 min after a peripheral intravenous bolus injection of 2.5 g Levovist. The intensity of the doppler signal was measured and used to plot time-intensity curves.

FINDINGS

Patients with cirrhosis showed a much earlier onset of enhancement (arrival time; mean 18.3 s) and peak enhancement (mean 55.5 s) than controls (49.8 s and 97.5 s) or patients with non-cirrhotic diffuse liver disease (35.8 s and 79.7 s). All patients with cirrhosis had an arrival time of the bolus of less than 24 s, whereas the arrival time was 24 s or more in 22 of the 23 other participants. Peak enhancement was higher in patients with cirrhosis (mean 48.7 units) than in the other two groups (12.5 and 12.3 units, respectively). We found highly significant differences between the patients with cirrhosis and each of the other two groups for all variables (p<0.005), whereas we found no significant differences between non-cirrhotic patients and controls.

INTERPRETATION

Our preliminary study suggests that analysis of liver transit time of a bolus of ultrasound contrast agent provides useful information about haemodynamic changes in patients with cirrhosis. Measurement of the arrival time of the bolus allows discrimination of patients with cirrhosis from controls and from patients with non-cirrhotic diffuse liver disease, and has potential as a non-invasive test for cirrhosis.

Improved imaging of liver metastases with stimulated acoustic emission in the late phase of enhancement with the US contrast agent SH U 508A: early experience

PURPOSE

To see whether stimulated acoustic emission (SAE) in the liver parenchyma in the late phase of enhancement with SH U 508A increases the conspicuity of occult metastases at ultrasonography (US).

MATERIALS AND METHODS

Eighteen patients with known hypo- or hypervascular hepatic metastases underwent US after SH U 508A administration, after a delay of at least 5 minutes, to ensure decay of blood pool enhancement. In 16 patients with visible metastases, conspicuity was compared on registered SAE and gray-scale scans by two blinded readers and by using computerized analysis of relative gray-scale and color Doppler conspicuity scores inside and outside the lesion. In nine patients, areas suspected of being involved but without definite gray-scale masses were imaged in the same way. Paired sections were analyzed by two blinded readers looking for parenchymal color defects without corresponding gray-scale masses; nine control images from three healthy volunteers were also included.

RESULTS

Intense, transient parenchymal SAE was seen in all subjects. All metastases appeared as areas of reduced or absent signal. The conspicuity score was 80% for SAE versus 9% for gray-scale US (P < .001, Wilcoxon signed rank test). SAE-specific defects were seen in all patients but in none of the volunteers. Metastases seen on SAE but undetectable on gray-scale images were proved in three patients.

CONCLUSION

SAE with SH U 508A improves the conspicuity of metastases. SAE-specific defects may reveal isoechoic or subtle metastases.

Liver vascular transit time analyzed with dynamic hepatic venography with bolus injections of an US contrast agent: early experience in seven patients with metastases

Spectral Doppler intensitometry to study transit of a bolus of an ultrasonographic (US) contrast agent in the hepatic veins was performed in seven patients suspected of having liver metastases and seven control subjects. All control subjects had a late response (rise time, > 25 seconds; time to peak intensity, > 45 seconds), whereas six of seven patients had an early response (rise time, < 25 seconds; time to peak intensity, < 45 seconds) (P < .01).

Prolongation and optimization of Doppler enhancement with a microbubble US contrast agent by using continuous infusion: preliminary experience

PURPOSE

To investigate whether continuous infusion of an echo-enhancing contrast agent for up to 15 minutes can provide uniform and prolonged enhancement.

MATERIALS AND METHODS

Six volunteers each received one bolus and three infusions of a microbubble contrast agent over 6-15 minutes at (a) a standard rate (mean, 2.08 mL/min), (b) a fast rate at twice the standard rate, and (c) a slow rate at half the standard rate. Spectral Doppler intensitometry of the femoral artery was performed for all infusions. Spectral Doppler ultrasound (US) scans of the femoral artery and color Doppler US scans of the carotid artery were subjectively assessed.

RESULTS

All infusions provided an equilibrium plateau of constant prolonged enhancement starting after 1-2 minutes and lasting until the end of the infusion. Enhancement at the plateau was +13 dB (slow rate), +17.1 dB (standard rate), and +18.3 dB (fast rate) compared with baseline. Saturation artifacts with infusions were markedly fewer than those with bolus injections. Dose effectiveness (duration of enhancement that measured at least 7.5 dB per gram of contrast agent) was markedly improved with the infusions, from 0.8 min/g for the bolus to 2.6 min/g for the slow infusion.

CONCLUSION

Continuous infusion of the microbubble contrast agent provided prolonged and uniform enhancement of Doppler signals and improved image quality by minimizing saturation artifacts.

The ureteric jet index: a novel measure of divided renal function

The aim of this study was to evaluate an index of divided renal function based on the quantification of the ureteric jets seen on colour Doppler ultrasound of the bladder. Thirty-one patients attending for scintigraphic renography underwent colour Doppler ultrasound with video recording for 5 min. Divided renal function was calculated as the proportion of jets from the right-sided orifice ('jet index'). This was compared with the corresponding 'scintigraphic index' found using Patlak-Rutland graphical analysis. Absolute discrepancies were calculated. Twenty-eight of thirty-one (90%) of studies were diagnostic for the calculation of jet indices. The mean jet index was 52% (n=28, SEM=5.8%) compared to a mean scintigraphic index of 54% (n = 28, SEM = 4.0%). The two scores were correlated, with a correlation coefficient of 0.72 and the median absolute difference between the two scores was 7.7%. Forty-three per cent (12/28) of subjects had discrepancies in the two scores of 5% or less. The score differences, however, showed a highly skewed distribution with 32% (9/28) subjects showing discrepancies over 20%. This discordant group (> 20% difference) included three patients with functional pelviureteric obstruction, one with a pelvic mass and one with an underfilled bladder. Two patients with very poor quality jets had impaired renal function. In one case, the index improved after angioplasty for renal artery stenosis. This simple test is a useful adjunct to urinary tract ultrasound but should be interpreted alongside evidence of renal obstruction, and complements rather than replaces existing tests.

Power Doppler US of the normal prepubertal testis: does it live up to its promises?

PURPOSE

To assess whether power Doppler ultrasound (US) improves the detection of flow in normal prepubertal testes.

MATERIALS AND METHODS

Seventy-two normal testes of 38 prepubertal boys (age range, 2 weeks to 12.5 years) were scanned with color and power Doppler US (7-MHz transducer). The two modalities were compared subjectively to determine which one was more sensitive for detection of flow. Only reproducible intratesticular flow signals were considered positive; capsular flow was disregarded.

RESULTS

Power Doppler US depicted flow in 50 testes (69%), while color Doppler US depicted flow in 47 testes (65%, not statistically significant). Power and color Doppler US combined depicted flow in 57 testes (79%), which was significant when compared with color Doppler US alone (P = .002). Detection of flow was subjectively easier with power Doppler US in 10 of 72 testes, while it was easier with color Doppler US in 14 of 72 testes. Motion artifacts were greater with power Doppler US.

CONCLUSION

Power Doppler US was equally sensitive as conventional color Doppler US in the detection of flow in normal prepubertal testes. Combining both modalities improved detection of flow in 14% of cases and may be useful in excluding torsion in children. For a positive preoperative diagnosis of torsion in children, radionuclide scintigraphy remains the imaging modality of choice.

Spontaneous dissections of the internal carotid artery: appearances on colour Doppler ultrasound

Spontaneous dissection of the internal carotid artery (ICA) is an unusual finding. We present an analysis of five patients (aged 40-60 years) with ICA dissections, describing the various flow patterns detected on colour Doppler ultrasound. Particular attention was paid to the presence of a dual lumen, the direction of flow in the false lumen and the velocity/spectral broadening of the Doppler trace obtained from the true and false lumens. Four different patterns were observed. Narrowing of the true lumen by the false lumen thrombus was seen in two cases with a low velocity Doppler waveform; three cases had a patent false lumen ("double lumen" pattern); the direction of flow in the patent false lumen varied from being (i) forward, (ii) reversed and (iii) bidirectional. The flow dynamics in carotid dissections are complex and are primarily dependent upon the presence of thrombus within the false lumen, the entry and exit flaps if the false lumen is patent, the motion of the flap wall and the extent of the dissection. They illustrate the diverse nature of the disease and Doppler ultrasound plays an important role in the imaging of ICA dissections.

Automated quantification of color Doppler signals: a preliminary study in breast tumors

PURPOSE

To quantify color Doppler (CD) signals reflected by breast lesions to improve differential diagnosis and serial comparisons.

MATERIALS AND METHODS

Frame-grabbed color-capture scans were remapped to original velocities on a pixel-by-pixel basis for statistical analysis. Total CD area and its percentage, peak and mean velocities, standard deviation of velocity, and integral CD velocity and its percentage were calculated. These indexes were applied to scans of 44 cancers, 16 fibroadenomas, and 14 benign breast changes in 74 patients.

RESULTS

With the region of interest confined to the lesion and a 5-mm margin, no CD signals were reflected by the benign breast changes. All carcinomas and 12 fibroadenomas (those that were vascular) reflected CD signals, and, except for mean and peak velocity, all scores for cancers were significantly higher than for fibroadenomas (P < .0001). Integral CD velocity was the best discriminator, with no overlap between carcinomas (range, 1,128-50,228 cm3/sec) and fibroadenomas (range, 0-1,027 cm3/sec).

CONCLUSION

Automatic CD quantification improved differential diagnosis of breast masses.

Device to enhance visibility of needle or catheter tip at color Doppler US

The authors tested a device that allows the tip of a needle to be visualized at color Doppler ultrasonography. The device directs an oscillating air column through a 0.016-inch inner-diameter hollow stylet, creating movement at only the needle tip. The movement is reliably and accurately displayed as a beacon of color at depths of 15 cm in vitro.

Adaptive speckle reduction for improving the differential diagnosis of breast lesions

Adaptive speckle reduction could mask diagnostic features and adversely affect diagnosis of focal breast lesions. Four radiologists assessed focal breast lesions (29 malignant and 31 benign) by blind review of representative static B-mode scans before and after adaptive speckle reduction processing, scoring 14 diagnostic features for breast cancer and recording their opinions on the diagnosis and on how adaptive speckle reduction affected interpretation of each feature. No adverse affect on diagnosis of malignant (P = 0.756) or benign (P = 1.000) breast lesions was found, despite some differences in scoring of the diagnostic features after adaptive speckle reduction. Observer recognition of most diagnostic features was easier after adaptive speckle reduction (e.g., edge definition [50% of cases], edge regularity [40%], lesion texture [44%], and lesion echogenicity [35%]).

Case report: diffuse fatty infiltration of the renal parenchyma secondary to bilateral angiomyolipomas--features on ultrasound and computed tomography

A case is described where ultrasound demonstrated diffusely increased echogenicity in massively enlarged kidneys. Computed tomography confirmed fatty replacement of the renal parenchyma, allowing a confident diagnosis of multiple bilateral angiomyolipomas in a clinical setting of tuberous sclerosis. This is the first ultrasound demonstration of such diffusely echogenic kidneys in angiomyolipoma.

Case report: retroperitoneal varices mimicking a mass: diagnosis on colour Doppler

Retroperitoneal varices may occasionally resemble retroperitoneal masses on computed tomography and B-mode ultrasound. Biopsy could be disastrous in this situation and angiography has previously been required to establish the diagnosis in suspected cases. This unusual problem can nowadays be readily diagnosed by colour Doppler. We report a case in which retroperitoneal varices were initially misinterpreted on B-mode ultrasound as retroperitoneal masses, but colour Doppler established the diagnosis without the need for further investigations.