Contrast-enhanced ultrasound for extrahepatic lesions: preliminary experience

Diagnostic value of enhanced-contrast ultrasound for cesarean scar pregnancy: A systematic review

BACKGROUND

Cesarean scar pregnancy, an uncommon ectopic pregnancy in which the embryo is implanted in the cesarean scar, poses significant risks without prompt diagnosis and treatment. Its prevalence has risen alongside increased cesarean section rates. Despite various treatment approaches, consensus remains elusive. Ultrasonography, particularly contrast-enhanced ultrasonography, shows promise in cesarean scar pregnancy diagnosis.

MAIN BODY

This systematic review, following PRISMA guidelines, explores contrast-enhanced ultrasound's diagnostic potential in cesarean scar pregnancy. We searched PubMed, Scopus, Web of Science, and Google Scholar up to August 2023. Selection involved two stages: title/abstract screening and full-text assessment. The included studies investigated contrast-enhanced ultrasound's diagnostic value in cesarean scar pregnancy, provided adequate data, and were peer-reviewed in English. Quality assessment followed the QUADAS-2 criteria. We extracted the diagnostic accuracy metrics: sensitivity, specificity, and accuracy. Out of 193 records, five studies met the inclusion criteria (2016-2020, China). Contrast-enhanced ultrasound displayed sensitivities of 77%-100% and specificities of 95%-100%. Two studies reported accuracy of 96.9%-97.8%. Compared with conventional ultrasound, contrast-enhanced ultrasound exhibited superior sensitivity, specificity, and accuracy. It also outperformed transvaginal ultrasound.

CONCLUSION

Enhanced-contrast ultrasound holds promise for diagnosing and managing cesarean scar pregnancy by visualizing scar vascularization in real-time, thereby reducing severe complication risks. This review highlights contrast-enhanced ultrasound as a transformative diagnostic tool for cesarean scar pregnancy management, despite existing evidence limitations.

Contrast-enhanced ultrasound (CEUS) in blunt abdominal trauma

Baseline ultrasound is essential in the early assessment of patients with a huge haemoperitoneum undergoing an immediate abdominal surgery; nevertheless, even with a highly experienced operator, it is not sufficient to exclude parenchymal injuries. More recently, a new ultrasound technique using second generation contrast agents, named contrast-enhanced ultrasound (CEUS) has been developed. This technique allows all the vascular phase to be performed in real time, increasing ultrasound capability to detect parenchymal injuries, enhancing some qualitative findings, such as lesion extension, margins and its relationship with capsule and vessels. CEUS has been demonstrated to be almost as sensitive as contrast-enhanced CT in the detection of traumatic injuries in patients with low-energy isolated abdominal trauma, with levels of sensitivity and specificity up to 95%. Several studies demonstrated its ability to detect lesions occurring in the liver, spleen, pancreas and kidneys and also to recognize active bleeding as hyperechoic bands appearing as round or oval spots of variable size. Its role seems to be really relevant in paediatric patients, thus avoiding a routine exposure to ionizing radiation. Nevertheless, CEUS is strongly operator dependent, and it has some limitations, such as the cost of contrast media, lack of panoramicity, the difficulty to explore some deep regions and the poor ability to detect injuries to the urinary tract. On the other hand, it is timesaving, and it has several advantages, such as its portability, the safety of contrast agent, the lack to ionizing radiation exposure and therefore its repeatability, which allows follow-up of those traumas managed conservatively, especially in cases of fertile females and paediatric patients.

Contrast-enhanced ultrasonographic findings in three dogs with lung lobe torsion

Lung lobe torsion is rare but life-threatening condition in the dog. Thoracic radiographs and conventional ultrasonography cannot be conclusive for the diagnosis, and computed tomography is useful but is limited by cost and availability. This report describes the findings of contrast-enhanced ultrasonography in 3 dogs with lung lobe torsion. Contrast-enhanced ultrasonography showed the absence or reduction of pulmonary vascularization secondary to twisting of the lung lobe around its bronchovascular pedicle in all three dogs. Moreover, contrast-enhanced ultrasonography distinguished partial pulmonary atelectasis from a lung lobe torsion. These preliminary results suggest that contrast-enhanced ultrasonography can improve the accuracy of conventional ultrasonography for detection of pulmonary blood flow compromise in dogs with lung lobe torsion.

Emergency radiology

US has a relevant role in the initial assessment of non-traumatic emergencies of the abdomen, sometimes being conclusive and some other times for selecting the patients for further imaging with CT. Injection of a contrast medium may give to the radiologist additional information to that obtained at baseline US and Doppler examination, since real-time, contrast-enhanced US (CEUS) may allow observing findings in the abdomen not recognizable at baseline US or even at color Doppler imaging. Extravascular use of microbubbles may also be useful in clinical practice to rapidly solve a number of unclear aspects. CEUS has a number of distinct advantages in acute patients, including its quickness, low invasiveness, and its possible bedside use. The information based on contrast enhancement is useful for initial diagnosis, therapeutic decision making, and follow-up of the critically ill patients. The purpose of this review is to illustrate the possibilities and limitations of abdominal CEUS in the acute setting, with special emphasis on the detection and characterization of acute inflammatory processes, infarcts, and hemorrhages.

Description of the use of contrast-enhanced ultrasonography in four dogs with pancreatic tumours

Canine pancreatic tumours are rare compared to human medicine and the detection and differentiation of pancreatic neoplasia is challenging with B-mode ultrasonography, which often leads to late clinical diagnosis and poor prognosis. This case report describes the findings of contrast-enhanced ultrasonography in four dogs with pancreatic adenocarcinoma or insulinoma. B-mode ultrasonography of the pancreas revealed a hypoechoic nodule in three dogs and heterogenous tissue in one dog. Contrast-enhanced ultrasonography was able to differentiate between two tumour types: adenocarcinomas showed hypoechoic and hypovascular lesions, whereas insulinomas showed uniformly hypervascular lesions. Contrast-enhanced ultrasonography findings were confirmed by cytology and/or histopathology. The results demonstrated that contrast-enhanced ultrasonography was able to establish different enhancement patterns between exocrine (adenocarcinoma) and endocrine (insulinoma) tumours in dogs.

High correlation between microbubble contrast-enhanced ultrasound, magnetic resonance and histopathology in the evaluation of hepatocellular carcinoma

OBJECTIVES

To evaluate the efficacy of microbubble contrast ultrasound in diagnosis of hepatocellular carcinoma and to compare its results with those of magnetic resonance and histopathology.

METHODS

A total of 29 patients suffering from chronic liver diseases and awaiting liver transplants at Hospital Israelita Albert Einstein were subject to magnetic resonance, microbubble contrast ultrasound, and excision liver biopsies.

RESULTS

Excellent agreement between magnetic resonance and microbubble contrast ultrasound was observed in this study. There was moderate agreement between both imaging methods and histopathology results.

CONCLUSION

Microbubble contrast ultrasound was as accurate as magnetic resonance to evaluate hepatocellular carcinoma. These results were confirmed by comparing both methods to histopathological diagnosis.

Minimal fat renal angiomyolipoma: the initial study with contrast-enhanced ultrasonography

We visualized minimal fat renal angiomyolipomas (AMLs) by contrast-enhanced ultrasonography (CEUS). Conventional ultrasound and CEUS images were retrospectively analyzed for solid minimal fat renal AML cases (n = 18) and solid renal cell carcinoma (RCC) cases (n = 105). We compared size, echogenicity and color flow signals with conventional ultrasound, and enhancement patterns with CEUS, in AMLs vs. RCCs. No significant differences in echogenicity and color flow signal existed between AMLs and RCCs using conventional ultrasound. With CEUS, slow centripetal enhancement in the cortical phase (83.3% of AMLs vs. 1.9% of RCCs) and homogeneous peak enhancement (100.0% of AMLs vs. 34.3% of RCCs) were valuable traits for differentiating these tumor types. These two CEUS-determined traits, combined, were differentiating criteria for minimal fat renal AMLs and RCCs; positive and negative predictive values were 100.0% and 97.2%, respectively. Slow centripetal enhancement in the cortical phase and homogeneous enhancement at peak are main features of CEUS-confirmed solid minimal fat renal AML.

Double contrast-enhanced ultrasonography for the preoperative evaluation of gastric cancer: a comparison to endoscopic ultrasonography with respect to histopathology

BACKGROUND

This study was designed to compare the accuracy of endoscopic ultrasound (EUS) with double contrast-enhanced ultrasound (DCUS) in the staging of gastric malignancies. DCUS is a transabdominal ultrasound technique using both intravenous and intraluminal contrast to enhance sonographic visualization.

METHODS

This retrospective study included 162 patients with biopsy-proven gastric cancer who underwent DCUS and EUS preoperatively with the ultrasound results compared with the pathologic findings of the resected specimens.

RESULTS

The overall accuracy of DCUS and EUS for tumor (T) staging was 77.2% and 74.7%, respectively. Comparison of ultrasound techniques for T staging revealed that DCUS was superior to EUS only for a tumor depth of T3 (chi-square, P = .025). Lymph nodes were staged correctly with DCUS and EUS in 78.4% and 57.4% of cases, respectively (chi-square, P = .001).

CONCLUSIONS

DCUS offers a noninvasive approach for the staging of gastric cancer. DCUS was comparable to EUS in tumor depth evaluation but offered an advantage in lymph node detection.

Contrast-enhanced ultrasound imaging of active bleeding associated with hepatic and splenic trauma

PURPOSE

The aim of this study was to evaluate contrast-enhanced ultrasound (CEUS) imaging of active bleeding from hepatic and splenic trauma.

MATERIALS AND METHODS

Three hundred and ninety-two patients with liver or/and spleen trauma (179 liver and 217 spleen injuries), who underwent CEUS examinations following contrast-enhanced computed tomography (CT), were enrolled in this retrospective study over a period of >4 years. CEUS detected contrast medium extravasation or pooling in 16% (63/396) of liver or spleen lesions in 61 patients, which was confirmed by contrast-enhanced CT. Special attention was paid to observing the presence, location, and characteristics of the extravasated or pooled contrast medium.

RESULTS

The CEUS detection rate for active bleeding was not different from that of contrast-enhanced CT (p=0.333). Information from surgery, minimally invasive treatment and conservative treatment was used as reference standard, and the sensitivities of the two techniques were not different (p=0.122). Of 63 lesions in 61 patients, CEUS showed that 74.6% (47/63) (21 liver lesions and 26 spleen lesions) presented contrast medium extravasation or pooling, both in the organ and out the capsule, in 14.3% (9/63) and only outside the capsule in 11.1% (7/63). CEUS imaging of active bleeding from hepatic and splenic trauma presented various characteristics, and the sizes and shapes of the active bleeding due to contrast medium extravasation or pooling were variable.

CONCLUSIONS

CEUS can show the active bleeding associated with hepatic and splenic trauma with various imaging characteristics, thus making it possible to diagnose active bleeding using CEUS.

Contrast-enhanced ultrasound using a time-intensity curve for the diagnosis of renal cell carcinoma

OBJECTIVE

• To evaluate the usefulness of contrast-enhanced ultrasound (CEUS) for the diagnosis of renal cell carcinoma by employing a time-intensity curve (TIC).

PATIENTS AND METHODS

• From May 2008 to October 2009, CEUS was performed prior to surgery in 30 patients with renal masses. • In all, 10 of the 30 patients had cystic renal masses. The final diagnoses of all patients were pathologically confirmed. Contrast enhancement as a function of time was measured in two (tumour or solid component of cystic lesions and normal parenchyma) regions of interest (ROI) and TICs were obtained. • The time to the contrast enhancement peak (TTP), intensity change from the baseline to peak (ΔI) and ΔI/TTP of the tumour and the normal parenchyma were measured from the TIC.

RESULTS

• Pathological diagnoses were renal cell carcinoma in 30 patients. • The TTP of the cancer was shorter than that of the normal parenchyma in all cases (6.0 ± 2.0 vs 10.4 ± 3.0 s; P < 0.0001). • The ΔI did not differ between the cancer and normal parenchyma [21.3 ± 5.9 vs 20.9 ± 7.0 decibels (db); P= 0.68]; the ΔI/TTP of the cancer was significantly higher than that of the normal parenchyma (3.9 ± 1.4 vs 2.2 ± 0.94 db/s; P < 0.0001). • TIC patterns of solid cancer and cystic cancer were very similar.

CONCLUSIONS

• An objective and quantitative diagnosis of renal cell carcinoma by CEUS using a second-generation ultrasound contrast agent can be made by employing a TIC. • The TIC patterns of solid and cystic cancers were very similar, despite their morphological and vascular differences. • CEUS using TIC is a promising tool in the diagnosis of cystic renal cancer.

Contrast-enhanced ultrasound features of primary splenic lymphoma

We report a case of primary splenic lymphoma incidentally detected on abdominal ultrasound as a well-defined homogenous hypoechoic splenic mass. Further characterization with contrast-enhanced ultrasound showed the mass to enhance homogenously during the arterial phase to a degree similar to that of the normal splenic parenchyma followed by rapid washout becoming hypoenhanced on delayed phase.

Renal cell carcinoma and renal angiomyolipoma: differential diagnosis with real-time contrast-enhanced ultrasonography

OBJECTIVE

The purpose of this study was to evaluate the usefulness of contrast-enhanced ultrasonography (CEUS) in differentiating renal cell carcinoma (RCC) from renal angiomyolipoma (RAML).

METHODS

One hundred nineteen patients with 126 renal lesions (33 RAMLs and 93 RCCs) who had undergone CEUS were retrospectively studied. All of the lesions were histopathologically or clinical proved. Contrast-enhanced ultrasonography was performed using low-acoustic power modes and a sulfur hexafluoride-filled microbubble contrast agent. The baseline sonograms and CEUS images were retrospectively analyzed in consensus by 2 radiologists. The tumor echogenicity, enhancement patterns, and degree of enhancement at different phases were evaluated. The diagnostic efficacy of CEUS in differentiating the two diseases was computed and compared.

RESULTS

On CEUS, the features of wash-out from hyperenhancement or isoenhancement to hypoenhancement over time (observed in 3.0% of RAMLs and 71.0% of RCCs; P < .001), heterogeneous enhancement (observed in 12.1% of RAMLs and 74.2% of RCCs; P < .001), and an enhanced perilesional rim (observed in 3.0% of RAMLs and 79.6% of RCCs; P < .001) achieved significant difference between RCCs and RAMLs. Early wash-out and heterogeneous enhancement or peritumoral rim enhancement yielded the highest diagnostic capability in differentiating RCC from RAML. The corresponding sensitivity, specificity, positive predictive value, negative predictive value, and accuracy were 88.2% (82 of 93), 97.0% (32 of 33), 98.8% (82 of 83), 74.4% (32 of 43), and 90.5% (114 of 126), respectively.

CONCLUSIONS

The CEUS features of early wash-out, heterogeneous enhancement, and an enhanced peritumoral rim highly suggest RCC, whereas homogeneous enhancement and prolonged enhancement are characteristic manifestations of RAML. Contrast-enhanced ultrasonography is valuable in differentiating RCC from RAML.

Clear cell renal cell carcinoma: contrast-enhanced ultrasound features relation to tumor size

OBJECTIVES

To analyze the contrast-enhanced ultrasound (CEUS) features of clear cell renal cell carcinoma (CCRCC) in relation to tumor size.

MATERIALS AND METHODS

The CEUS appearance of 92 CCRCCs confirmed pathologically were retrospectively analyzed. Tumor size was stratified into six groups with a 1cm interval. For each lesion, the degree of enhancement, the homogeneity of enhancement and the presence of pseudocapsule sign were evaluated and compared with the pathologic findings.

RESULTS

The tumors of groups I-VI were counted for 13, 26, 21, 11, 10 and 11, respectively. All the CCRCCs mainly showed a marked enhancement, and there was no statistically significance between the degree of enhancement and tumor size (P>0.05). However, both homogeneity of enhancement and frequency of pseudocapsule correlated well with the tumor size (P<0.01). Homogeneous enhancement was shown in 85%, 65%, 19%, 9%, 0% and 0% of the tumors in the six groups, respectively. In tumors < or =3cm the frequency (72%) of homogeneity was significantly higher than in tumors >3cm (9%; P<0.01). The detection rate of pseudocapsule sign in the six group was 23%, 62%, 71%, 64%, 50% and 0%, respectively. The frequency of pseudocapsule sign was significantly higher in tumors 2.1-5cm than <2cm and >5cm (66%, 23%, 24%, respectively; P<0.01). On the pathologic examinations, the mean MVD was significantly higher in marked enhancement tumors than slight enhancement tumors (46.0+/-15.9, 27.5+/-8.3, respectively; P<0.01). Any tumors with a heterogeneous enhancement pattern were accompanied by intratumoral necrosis or cysts on histologic specimen. A pseudocapsule was seen at pathology in all the 46 cases with perilesional enhancement and 4 of 46 tumors without perilesional enhancement at CEUS.

CONCLUSION

CEUS features of CCRCCs vary with the size of the tumor, especially in the homogeneity of enhancement and the presence of pseudocapsule sign. CEUS is effective in demonstrating the sonographic visualization of tumoral characteristics.

Hemostatic agents injected directly into hepatic injury sites for liver trauma hemorrhage under the guidance of contrast-enhanced ultrasound: an animal experiment

We investigated whether direct injection of hemostatic agents into injury sites under the guidance of contrast-enhanced ultrasound (CEUS) can decrease blood loss from liver trauma. Twelve adult healthy dogs underwent laparotomy, and a hepatic wound (6.0 x 4.5 cm) was created in each dog. All animals were divided randomly into two groups: the treatment group and the control group. In the treatment group, hemocoagulase Atrox (Solco Basle Ltd., Birsfelden, Switzerland) and absorbable cyanoacrylate were injected directly into the liver injury sites, and 0.9% normal saline was injected into the injury sites in the control group. Resuscitation volume in the treatment group was less than that in the control group (55 +/- 12 mL vs. 105 +/- 23 mL, p < 0.001). The control group presented bleeding from liver injury sites. Times of bleeding at the injury site in the treatment groups were 6 +/- 1 s. Both groups presented an-echo and/or hypo-echo contrast regions, with contrast material pooling in the injury sites before the therapy. After the injection, the contrast material pooling disappeared in the treatment group observed by CEUS. Gross examination of liver tissue revealed that the injury site that had been treated was covered by clot and glue membrane. Histopathologic examination showed that there was hemostitic glue embolizing the microvessels and inflammatory cell infiltration among hepatocytes. Direct injection of hemocoagulase Atrox and cyanoacrylate into the liver injury sites guided by CEUS can effectively reduce blood loss from liver trauma within a short time. This experimental study may suggest a possible treatment for liver trauma hemorrhage and provide an experimental evidence for treating blunt abdominal parenchyma organs trauma under the guidance of CEUS.

Contrast-enhanced sonographic guidance for local injection of a hemostatic agent for management of blunt hepatic hemorrhage: a canine study

OBJECTIVE

The purpose of this study was to determine whether injection of hemostatic agents directly into an injury site under the guidance of contrast-enhanced sonography can effectively control hemorrhage due to hepatic trauma.

MATERIALS AND METHODS

Fifteen mixed-breed dogs 2-3 years old and weighing 17-20 kg were anesthetized with intramuscular pentobarbital sodium (30 mg/kg). A special impacting device was used to induce hepatic trauma with a mean force of 5.3 +/- 0.3 kN. Twelve of the 15 dogs had hepatic injuries with a grade of 3-4 or 4. The 12 dogs were divided into treatment and control groups. In the treatment group, hemocoagulase atrox (1 Klobusitzky unit) and alpha-cyanoacrylate (1 mL) were administered by transcutaneous injection into the injury site and the bleeding site, respectively, under the guidance of contrast-enhanced sonography. The control group received injections of 0.9% normal saline solution.

RESULTS

After injection into the treatment group, no active bleeding was observed at the liver injury site. In the control group, evidence of active bleeding was present on contrast-enhanced sonograms. Laparotomy of the treatment group showed that hepatic injuries had been covered and adhered by clots and the glue membrane of the hemostatic agents and that free intraperitoneal blood volume was significantly less than in the control group (p < 0.001). Bleeding did not stop in the control group.

CONCLUSION

In dogs, transcutaneous local injection of hemostatic agents can effectively reduce blood loss due to severe liver trauma. Because it is simple, convenient, and effective, the technique may be an alternative for bedside and battlefield management of hepatic hemorrhage due to trauma.

Impact of contrast-enhanced ultrasonography in a tertiary clinical practice

OBJECTIVE

The purpose of this study was to assess the impact of contrast-enhanced ultrasonography (CEUS) of the liver in a tertiary clinical practice.

METHODS

One thousand forty consecutive CEUS examinations performed over 30 months for mass characterization were reviewed to determine their source, accuracy, and clinical impact.

RESULTS

Two hundred seventy-five (26.4%) of 1040 examinations were motivated by incidental detection of a mass at routine ultrasonography; 765 (73.6%) were clinical referrals, most often for characterization of a mass in a high-risk patient scanned for hepatoma surveillance or characterization of an indeterminate mass after prior imaging. Clinician referrals increased from 57 in the first 6 months after CEUS introduction to 158 in the last 6 months of the study. Surveillance scans yielded 78 confirmed hepatocellular carcinomas characterized on CEUS at the time of identification. Contrast-enhanced ultrasonography was accurate in 233 (89.2%) of 261 with histologic proof, including 208 malignant lesions. Clinical impact included reduced referrals for other imaging in 226 (21.7%) of 1040 patients, decreased time to diagnosis in 390 (37.5%), and successful guidance for ablation therapy in 26 (2.5%). A positive change in management occurred in 182 (17.5%) of 1040, including alteration of a previous diagnosis, a diagnosis made by CEUS after indeterminate prior imaging, and a diagnosis upstaged by CEUS. Negative impacts included delayed management in 8 (0.8%) small hepatocellular carcinomas misdiagnosed as benign lesions and wrong management of a solitary sclerotic hemangioma, in a high-risk patient for hepatoma, misdiagnosed as a malignant tumor on CEUS, computed tomography, and magnetic resonance imaging, leading to its surgical removal.

CONCLUSIONS

Contrast-enhanced ultrasonography has a positive impact on clinical management, providing rapid, accurate diagnosis of incidentally detected masses and resolving nodules on surveillance scans and indeterminate masses on other imaging.

Contrast-enhanced ultrasound for diagnosis of prostate cancer and kidney lesions

PURPOSE OF REVIEW

Conventional ultrasonography of both, kidney and prostate, is limited due to the poor contrast of B-mode imaging for parenchymal disease and limited sensitivity of colour Doppler for the detection of capillaries and deep pedicular vessels. Contrast-enhanced ultrasound (CEUS) overcomes these limitations.

RECENT FINDINGS

CEUS investigates the blood flow of the prostate, allows for prostate cancer visualization and for targeted biopsies. Comparisons between systematic and CEUS-targeted biopsies have shown that the targeted approach detects more cancers with a lower number of biopsy cores and with higher Gleason scores compared with the systematic approach. Also the kidney offers promising applications as CEUS improves the detection of abnormal microvascular and macrovascular disorders.

SUMMARY

In recent literature CEUS has shown its value for diagnosis of both, prostate cancer and kidney lesions. This paper describes recent improvements and future perspectives of CEUS.

Splenic focal lesions as manifestation of sarcoidosis: Characterization with contrast-enhanced sonography

We report the case of a 74-year-old woman with elevated liver enzyme levels in whom abdominal sonographic examination revealed a diffusely heterogeneous liver parenchyma and multiple hypoechoic subcentimetric splenic nodules. Contrast-enhanced sonography (CEUS) revealed that the splenic focal lesions did not enhance. CT examination revealed a low-density, multinodular pattern both in the liver and in the spleen. Core biopsy of 1 hepatic nodule revealed noncaseating epithelioid cell granuloma, and the patient was diagnosed with systemic sarcoidosis. CEUS has shown to be useful in the diagnosis of focal hepatic lesions, but studies referring to splenic lesions are lacking.

Second-generation sonographic contrast agents in the evaluation of renal trauma

PURPOSE

The purpose of this study was to define the indications, diagnostic accuracy and limitations of second-generation sonographic contrast agents in the evaluation of patients with renal trauma.

MATERIALS AND METHODS

Between March 2004 and April 2005, 277 patients with blunt abdominal trauma were evaluated. Twenty-eight out of 277 patients had renal lesions, the severity of which was graded according to the organ injury severity scale of the American Association for the Surgery of Trauma (AAST). All the patients enrolled in the study had minor trauma and were evaluated with baseline ultrasound (US), contrast-enhanced US after injection of a second-generation contrast agent (SonoVue) and, if positive, with multiphasic multidetector computed tomography (MDCT).

RESULTS

Five out of 28 traumatic parenchymal lesions with perirenal fluid collection were identified at baseline US. All 28 renal parenchymal lesions, with or without perirenal or retroperitoneal haematoma, were identified at contrast-enhanced US. Multiphase MDCT confirmed all the cases that were positive at contrast-enhanced US and demonstrated the integrity of the urinary tract in the delayed phase.

CONCLUSIONS

Our experience confirmed the diagnostic accuracy of second-generation sonographic contrast material both for diagnosis and for appropriate patient management. In particular, contrast-enhanced sonography proved to be a reliable technique for the evaluation and follow-up of low-grade renal injuries. Its main advantage is reduced radiation exposure, as fewer MDCT examinations are needed, whereas its limitation is the high cost of the technique if used in unselected patients.

Ultrasonography of Renal Masses Using Contrast Pulse Sequence Imaging: A Pilot Study

BACKGROUND AND PURPOSE

The use of contrast-enhanced ultrasonography for imaging of renal masses was first described in 1994. Since then, many new techniques for visualization of the effect of microbubble contrast agents have been developed. In this pilot study, a small number of patients was investigated with contrast pulse sequence imaging (CPS), and the characteristics of this perfusion imaging technique were evaluated subjectively and judged against the clinical diagnosis and histology findings when available. The purpose of this pilot study was to describe CPS imaging in several cases.

PATIENTS AND METHODS

Eighteen patients with 20 previously identified renal masses were examined with CPS. Perfusion imaging was compared with clinical diagnosis and with histologic findings when available.

RESULTS

Nineteen masses were visible. Various enhancement patterns could be observed, and interpretations of CPS characteristics are described. In carcinomas, inhomogeneous enhancement patterns were observed, and areas without enhancement inside the inhomogeneous lesions corresponded to necrotic areas in histologic specimens. All simple cysts and complex benign cysts showed absence of enhancement inside or in the wall of the lesion and a regular shape.

CONCLUSION

To our knowledge, this is the first study in which the characteristics of CPS imaging of renal masses have been related to clinical diagnoses and histologic features. From the results of this pilot project, we conclude that CPS is a promising technique to determine perfusion patterns in the kidney.

Contrast-enhanced sonography of the spleen

Sonography is frequently the first imaging modality employed to evaluate the spleen. Nevertheless, splenic abnormalities frequently determine subtle changes in echogenicity and may be overlooked. Additionally, splenic disorders have a nonspecific appearance, mostly appearing as hypoechoic defects. Difficulties in differential diagnosis are not uncommon, with splenic infarctions resembling, for example, focal lesions. Color Doppler is usually of limited additional value. Instead, the spleen is optimally suited for contrast-enhanced sonography, being superficial, small, and homogeneous, and showing intense and persistent contrast enhancement. Scarcely evident abnormalities become evident after contrast medium injection. Additional information can be obtained in many clinical scenarios, including blunt trauma, left flank pain, lymphoma, and incidental detection of splenic abnormalities.

Contrast-enhanced ultrasound (CEUS) for the study of peripheral lung lesions: a preliminary study

The use of contrast-enhanced ultrasound (CEUS) for the study of peripheral lung lesions has never been systematically investigated. We evaluated the CEUS patterns of 98 peripheral lung lesions before performing US-guided fine-needle biopsies (FNB). The examinations were done with an Esaote Technos MPX scanner in the harmonic mode with a mechanical index of 0.04 or less. Contrast enhancement was achieved with a 4.8 mL bolus of SonoVue (Bracco) administered via an antecubital vein. All FNBs performed under CEUS guidance were adequate for pathologic diagnosis. Seventy-eight lesions were malignant: 33 (41.9%) were adenocarcinomas, 29 (36.5%) were squamous-cell carcinomas, 13 (17.6%) were undifferentiated large-cell carcinomas and the remaining three (4.1%) were small-cell carcinomas. All presented intralesional enhancement consistent with tumor neovascularization. In some cases, there were unenhanced areas consistent with zones of necrosis and these areas were avoided during FNB. The other 20 lesions were benign (four lipomas, two fibrous lung tumor, two noncaseous granulomas, six abscesses, one rheumatoid nodule, one histiocytosis X, one chondroid hamartoma, one sclerosing hemangioma, two sarcoid nodules) and none presented intralesional enhancement. This initial and admittedly limited experience suggests that CEUS may provide diagnostically useful information on peripheral lung lesions and increase the diagnostic yield of transthoracic FNB by reducing the risk of inadequate tissue sampling.

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.

Ultrasonography of splenic abnormalities

AIM: This report gives a comprehensive overview of ultrasonography of splenic abnormalities. Certain ultrasonic features are also discussed with pathologic correlation.

METHODS: We review the typical ultrasonic characteristics of a wide range of splenic lesions, illustrating them with images obtained in our institution from 2000 to 2003. One hundred and three patients (47 men, 56 women), with a mean age of 54 years (range 9-92 years), were found to have an abnormal ultrasonic pattern of spleen.

RESULTS: We describe the ultrasonic features of various splenic lesions such as accessory spleen, splenomegaly, cysts, cavernous hemangiomas, lymphomas, abscesses, metastatic tumors, splenic infarctions, hematomas, and rupture, based on traditional gray-scale and color Doppler sonography.

CONCLUSION: Ultrasound is a widely available, noninvasive, and useful means of diagnosing splenic abnormalities. A combination of ultrasonic characteristics and clinical data may provide an accurate diagnosis. If the US appearance alone is not enough, US may also be used to guide biopsy of suspicious lesions.