Shellfish allergy and relation to iodinated contrast media: United Kingdom survey

AIM: To assess current practice of United Kingdom cardiologists with respect to patients with reported shellfish/iodine allergy, and in particular the use of iodinated contrast for elective coronary angiography.Moreover we have reviewed the current evidence-base and guidelines available in this area.METHODS: A questionnaire survey was send to 500senior United Kingdom cardiologists(almost 50% cardiologists registered with British Cardiovascular Society)using email and first 100 responses used to analyze practise. We involved cardiologists performing coronary angiograms routinely both at secondary and tertiary centres. Three specific questions relating to allergy were asked:(1) History of shellfish/iodine allergy in pre-angiography assessment;(2) Treatments offeredfor shellfish/iodine allergy individuals; and(3) Any specific treatment protocol for shellfish/iodine allergy cases. We aimed to establish routine practice in United Kingdom for patients undergoing elective coronary angiography. We also performed comprehensive PubMed search for the available evidence of relationship between shellfish/iodine allergy and contrast media.RESULTS: A total of 100 responses were received, representing 20% of all United Kingdom cardiologists. Ninety-three replies were received from consultant cardiologists, 4 from non-consultant grades and 3 from cardiology specialist nurses. Amongst the respondents, 66% routinely asked about a previous history of shellfish/iodine allergy. Fifty-six percent would pre-treat these patients with steroids and anti-histamines. The other 44% do nothing, or do nonspecific testing based on their personal experience as following:(1) Skin test with 1 mL of subcutaneous contrast before intravenous contrast;(2) Test dose 2 mL contrast before coronary injection;(3) Close observation for shellfish allergy patients; and(4) Minimal evidence that the steroid and anti-histamine regime is effective but it makes us feel better.CONCLUSION: There is no evidence that allergy to shellfish alters the risk of reaction to intravenous contrast more than any other allergy and asking about such allergies in pre-angiogram assessment will not provide any additional information except propagating the myth.

Value of MR contrast media in image-guided body interventions

In the past few years,there have been multiple advances in magnetic resonance (MR) instrumentation,in vivo devices,real-time imaging sequences and interventional procedures with new therapies.More recently,interventionists have started to use minimally invasive image-guided procedures and local therapies,which reduce the pain from conventional surgery and increase drug effectiveness,respectively.Local therapy also reduces the systemic dose and eliminates the toxic side effects of some drugs to other organs.The success of MR-guided procedures depends on visualization of the targets in 3D and precise deployment of ablation catheters,local therapies and devices.MR contrast media provide a wealth of tissue contrast and allows 3D and 4D image acquisitions.After the development of fast imaging sequences,the clinical applications of MR contrast media have been substantially expanded to include pre-during-and post-interventions.Prior to intervention,MR contrast media have the potential to localize and delineate pathologic tissues of vital organs,such as the brain,heart,breast,kidney,prostate,liver and uterus.They also offer other options such as labeling therapeutic agents or cells.During intervention,these agents have the capability to map blood vessels and enhance the contrast between the endovascular guidewire/catheters/devices,blood and tissues as well as direct therapies to the target.Furthermore,labeling therapeutic agents or cells aids in visualizing their delivery sites and tracking their tissue distribution.After intervention,MR contrast media have been used for assessing the efficacy of ablation and therapies.It should be noted that most image-guided procedures are under preclinical research and development.It can be concluded that MR contrast media have great value in preclinical and some clinical interventional procedures.Future applications of MR contrast media in image-guided procedures depend on their safety,tolerability,tissue specificity and effectiveness in demonstrating success of the interventions and therapies.

Transient small bowel angioedema due to intravenous iodinated contrast media

Three cases of transient proximal small bowel angioedema induced by intravenous administration of nonionic iodinated contrast media (CM) are presented.Computed tomography (CT) images in the venous phase displayed the proximal small bowel with circumferential thickening of the wall including the duodenum and proximal segment of the jejunum.The bowel wall was normal in non-enhanced images,and normal or inconspicuous in arterial phase enhanced images.In one of the three cases,the bowel wall was thickened in venous phase but disappeared in the 40 s delayed phase images.No filling defect was seen in the lumen of the superior mesenteric artery and vein.No peritoneal effusion or mesentery abnormality was found.Each of these patients reported only mild abdominal discomfort and recovered without specific treatment within a short time.Only one patient suffered mild diarrhea after scanning which had resolved by the following day.The transient anaphylactic small bowel angioedema due to intravenous iodinated contrast media was easily diagnosed based on its characteristic CT findings and clinical symptoms.Differential diagnosis may include inflammatory and ischemic bowel disease,as well as neoplasms.A three-phase CT protocol and good under-standing of this disorder are fundamentally important in the diagnosis of this condition.The supposed etiology behind the transient anaphylactic reaction to intravenous administration of iodinated CM in small bowel is similar to other CM-induced hypersensitive immediate reactions.The predilection location of transient anaphylactic bowel angioedema is the small intestine,particularly the proximal segment.A speculated cause may be the richer supply of vessels in the small intestine,ample mucous folds and loose connective tissue in the duodenum and the jejunum.

Studies on Hepatocyte-Targeting Magnetic Resonance Imaging Macromolecular Contrast Media

DTPA was covalently conjugated to the copolymer of L lysine and L tyrosine, then transchelated with Gd EDTA,the resultant polymer chelates were further reacted with 6 O bromoacetyl D galactose or methyl lactobionyloxyacetate to give PLT(Gd DTPA) with galactose moiety as liver targeting group.These macromolecular MRI contrast agents were characterized by means of FT IR, ICP AES, elementary analyses and UV Vis spectrophotometry. Their in vitro relaxivity and liver targeting property in mice were also investigated.

Protective Effect of Oral Steroid Premedication: Adverse Reactions to Nonionic Iodine Contrast Media for Computed Tomography

This study aimed to investigate the protective effect of oral steroid premedication in terms of adverse reactions to non-ionic contrast media. We investigated the incidence of adverse reactions among patients who underwent contrast-enhanced computed tomography. Patients in the premedication group took 30 mg of prednisolone orally the night before and on the morning of the scheduled computed tomography. Sixty-five patients received the same contrast media. Among them, 56 took prednisolone orally prior to the procedure (premedication without change of contrast media group) and nine without premedication (no premedication and no change of contrast media group). In total, 379 patients received different contrast media. Among them, 340 took prednisolone orally (premedication with change of contrast media group), while 39 did not take the premedication (no premedication with change of contrast media group). The adverse reaction rates in the premedication with change of contrast media and no premedication with change of contrast media groups were 1.8% (6/340 cases) and 2.6% (1/39 cases) (P = 0.54), respectively. The incidence of adverse reaction after the administration of non-ionic iodinated contrast media did not differ significantly based on whether an oral steroid was administered prior to compute tomography. Our evaluation is limited due to the small sample size of the contrast media-changed group. However, even if premedication with steroids is effective, it may only result in an adverse reaction reduction rate of ≤3%.

Effects of contrast media on the hepato-pancreato-biliary system

AIM： To determine the effects of high osmolarity contrast media （HOCM） and iso-osmolar contrast media （CM） application, with or without pressure, on hepato-pancreato-biliary （HPB） system. METHODS： Sixty rats were divided into six equal groups as follows： Group i： （0.9% NaCl, control）, Group 2： （diatrizoate meglumine Na, ionic HOCM, Urographin）, Group 3： （iodixanol, iso-osmolar nonionic CM, Visipaque）; each of which was applied without pressure, whereas the animals of the remaining three groups （1p, 2p, 3p） were subjected to the same CM with pressure. We performed a duodenal puncture and introduced a catheter into the ampulla. After the catheterization, 0.2 mL CM or 0.9% NaCI was injected with or without pressure. Blood samples were taken for biochemical evaluations. The histopathological examinations of liver, common bile duct, and pancreas were performed. RESULTS： There were no significant differences between the six groups for blood amylase, alanine aminotransferases, aspartate aminotransferases, bilirubin levels （P 〉 0.05）. Alkaline phosphatase and γ glutamyl transaminase levels were higher （P 〈 0.05） in the Urographin groups （2, 2p） than the Visipaque groups （3, 3p）, or control groups （1, 1p）. Hepatocyte necrosis, portal area inflammation, and Kupffer＇s cell hyperplasia were higher （P 〈 0.05） in the study groups than the control group. However, there were no significant differences （P 〉 0.05） between HOCM （2, 2p） and iso-osmolar CM （3, 3p） groups. Bile duct proliferation and regeneration in the Urographin groups （2, 2p） were significantly higher （P 〈 0.05） than the Visipaque~ groups （3, 3p） or the control groups （1, lp）. Although CM caused minor damage to the pancreas, there were no statistically significant differences （P 〉 0.05） between the groups. Application of the CM with pressure did not cause additional damage to the HPB system. CONCLUSION： Iso-osmolar, non-ionic CM could be more reliable than the ionic HOCM, whereas the application of pressure during the CM application had no effect on the HPB system.

Navigating nephrotoxic waters:A comprehensive overview of contrast-induced acute kidney injury prevention

Contrast-induced acute kidney injury(CI-AKI)is the third leading cause of acute kidney injury deriving from the intravascular administration of contrast media in diagnostic and therapeutic procedures and leading to longer in-hospital stay and increased short and long-term mortality.Its pathophysiology,although not well-established,revolves around medullary hypoxia paired with the direct toxicity of the substance to the kidney.Critically ill patients,as well as those with pre-existing renal disease and cardiovascular comorbidities,are more susceptible to CI-AKI.Despite the continuous research in the field of CI-AKI prevention,clinical practice is based mostly on periprocedural hydration.In this review,all the investigated methods of prevention are presented,with an emphasis on the latest evidence regarding the potential of RenalGuard and contrast removal systems for CI-AKI prevention in high-risk individuals.

Signal intensity changes of dentate nucleus on plain MR T1WI innasopharyngeal carcinoma patients after radiotherapy andmultiple injections of gadolinium-base contrast agent

Objective To observe changes of plain MR T1WI signal intensity of dentate nucleus in nasopharyngeal carcinoma patients after radiotherapy and multiple times of intravenous injection of gadolinium-based contrast agent(GBCA).Methods Fifty patients with pathologically confirmed nasopharyngeal carcinoma and received intensity-modulated radiotherapy were retrospectively enrolled as the nasopharyngeal carcinoma group,and 50 patients with other malignant tumors and without history of brain radiotherapy were retrospectively enrolled as the control group.All patients received yearly GBCA enhanced MR examinations for the nasopharynx or the head.T1WI signal intensities of the dentate nucleus and the pons on same plane were measured based on images in the year of confirmed diagnosis(recorded as the first year)and in the second to the fifth years.T1WI signal intensity ratio of year i(ranging from 1 to 5)was calculated with values of dentate nucleus divided by values of the pons(ΔSI i),while the percentage of relative changes of year j(ranging from 2 to 5)was calculated withΔSI j compared toΔSI 1(Rchange j).The values of these two parameters were compared,and the correlation ofΔSI and GBCA injection year-time was evaluated within each group.Results No significant difference of gender,age norΔSI 1 was found between groups(all P>0.05).The second to the fifth yearΔSI and Rchange in nasopharyngeal carcinoma group were all higher than those in control group(all P<0.05).Within both groups,ΔSI was positively correlated with GBCA injection year-time(both P<0.05).Conclusion Patients with nasopharyngeal carcinoma who underwent radiotherapy and multiple times of intravenous injection of GBCA tended to be found with gradually worsening GBCA deposition in dentate nucleus,for which radiotherapy might be a risk factor.

Thyroid Dysfunction in Children Exposed to Iodinated Contrast Media:A Meta-Analysis and Systematic Review

Iodinated contrast media(ICM)has the potential to cause thyroid dysfunction in some patients.However,it is unclear whether this relationship exists in children.We conducted a systematic review and meta-analysis aim to obtain a general overview of the relationship between ICM exposure and the risk of thyroid dysfunction in children.Methods:Computer search of Web of Science,EMbase,PubMed,Cochrane Library,collection of relevant literature on ICM and thyroid dysfunction in children,the search period was from the establishment of the database to July 2021.Meta-analysis was performed using Stata 14.0 software.Results:A total of 8 literatures with 3497 children.The incidence of hypothyroidism in children with ICM exposure was 0.05(95%CI:0.05,0.12),P<0.0001.Subgroup analysis showed that the incidence of hypothyroidism in ICM exposed children in the European region was 0.21(95%CI:0.13,0.30),P<0.0001,a statistically significant difference.Conclusion:The current evidence shows that children exposed to ICM are at risk for hypothyroidism,with a higher risk in neonates,especially children with congenital heart disease.

Role of contrast-enhanced ultrasonography in percutaneous radiofrequency ablation of liver metastases and efficacy evaluation

Objective： To retrospectively investigate the role of contrast-enhanced ultrasonography （CEUS） in percutaneous radiofrequency ablation （RFA） in patients with liver metastases and evaluate the therapeutic efficacy of RFA assisted by CEUS. Methods： From May 2004 to September 2010, 136 patients with 219 liver metastatic lesions received CEUS examination 1 h before RFA （CEUS group）, and other 126 patients with 216 lesions without CEUS examination in the earlier period were served as a historical control group. The mean tumor size was 3.2 cm and the mean tumor number was 1.6 in the CEUS group, while 3.4 cm and 1.7 in the control group, respectively （P〉0.05）. The clinical characteristics, recurrence results and survival outcomes were compared between two groups. Results： In the CEUS group, two isoechoic tumors were not demonstrated on unenhanced ultrasonography （US）, and 63 （47%） of 134 tumors examined with CEUS were 0.3 cm larger than with unenhanced US. Furthermore, in 18.4% of 136 patients, additional 1-3 tumors were detected on CEUS. The CEUS group showed higher early tumor necrosis and lower intrahepatic recurrence than the control group. The 3-year overall survival （OS） rate and the 3-year local recurrence-free survival （LRFS） rate in the CEUS group were 50.1% and 38.3%, in contrast to 25.3% and 19.3% in the control group, respectively （P=0.002 and P〈0.001）. Conclusions： CEUS provides important information for RFA treatment in patients with liver metastases and better therapeutic effect could be attained.

Preventing radiocontrast-induced nephropathy in chronic kidney disease patients undergoing coronary angiography

Radiocontrast-induced nephropathy(RCIN) is an acute and severe complication after coronary angiography,particularly for patients with pre-existing chronic kidney disease(CKD).It has been associated with both short-and long-term adverse outcomes,including the need for renal replacement therapy,increased length of hospital stay,major cardiac adverse events,and mortality.RCIN is generally defined as an increase in serum creatinine concentration of 0.5 mg/dL or 25%above baseline within 48 h after contrast administration.There is no effective therapy once injury has occurred,therefore,prevention is the cornerstone for all patients at risk for acute kidney injury(AKI).There is a small but growing body of evidence that prevention of AKI is associated with a reduction in later adverse outcomes.The optimal strategy for preventing RCIN has not yet been established.This review discusses the principal risk factors for RCIN,evaluates and summarizes the evidence for RCIN prophylaxis,and proposes recommendations for preventing RCIN in CKD patients undergoing coronary angiography.

Color Doppler velocity profile and contrast-enhanced ultrasonography in assessment of liver cirrhosis

BACKGROUND: This study was designed to probe the clinical value in assessing the degree of liver cirrhosis by using the arrival time of contrast agent in the right portal vein in contrast-enhanced ultrasonography, as well as the velocity and flow volume in the right portal vein using the color Doppler velocity profile technique. METHODS: Twenty-eight patients with HBV post-hepatic cirrhosis were grouped into compensated (13 patients) and decompensated cirrhosis (15); 30 patients without hepatic cirrhosis served as controls. Written informed consent was obtained from each patient. All the patients with hepatic cirrhosis were pathologically confirmed by percutaneous biopsy. SonoVue was injected to detect the arrival time in the right portal vein. The velocity and flow volume in the right portal vein were measured. The value of each parameter was compared for correlation analysis. RESULTS: The arrival time in the right portal vein in the cirrhosis group was much longer than that in the control group (24.92 +/- 1.34 vs. 20.81 +/- 0.55 sec, respectively, P<0.01). The mean velocity, maximal velocity and flow volume in the cirrhosis group were much lower than those in the control group (10.64 +/- 0.84 vs. 14.78 +/- 0.71 cm/sec, 13.68 +/- 1.02 vs. 17.30 +/- 0.68 cm/sec and 358.72 +/- 23.63 vs. 438.61 +/- 16.86 ml/min, respectively, P<0.01). With the development of cirrhosis, the arrival time in the right portal vein was longer (P<0.05), and the velocity and flow volume was lower (P<0.01). There was a negative correlation between arrival time and mean velocity, maximal velocity and flow volume in the right portal vein in the cirrhosis group (r=-0.547, P<0.01; r=-0.508, P<0.05; r=-0.471, P<0.05, respectively). CONCLUSIONS: With the development of liver cirrhosis, the arrival time of contrast agent in the right portal vein is gradually prolonged, whereas the velocity and flow volume in this vein decreases markedly, and there is a negative correlation between the results of the two methods.

Double contrast-enhanced two-dimensional and three-dimensional ultrasonography for evaluation of gastric lesions

AIM： To investigate the value of two-dimensional （2D） and three-dimensional （3D） double contrast-enhanced ultrasonography （DCUS） imaging for evaluation of gas- tric lesions. METHODS： 2D and 3D DCUS imaging with both oral and intravenous administrations of contrast agents was used to assess gastroscopiclly-confirmed gastric lesions in 46 patients with benign and malignant diseases. Initially, liquid-based ultrasound contrast agent （Xinzhang） was given orally at dose of 500-600 mL for conventional ultrasound examination of the gastric lesions, and then a microbubble-based contrast agent （SonoVue） was injected intravenously at dose of 1.2-2.4 mL in bolus fashion to assess the perfusion pattern of the lesions using contrast imaging modes. The parameters derived from time-intensity curves including the arrival time （AT）, time to peak （lq-P）, peak intensity （PI） and en- hanced intensity （EI） were measured on the 2D DCUS imaging. 3D DCUS of the lesions was acquired to dem- onstrate the value of this imaging mode. RESULTS： There were 22 cases with benign lesions including chronic gastritis （n= 5）, gastric ulcer （n = 9）, gastric polyps （n = 3）, gastric stromal tumors （n = 5）, and 24 cases with malignant lesions including gastric cancer （n = 20）, gastric cardia carcinoma （n = 3） and post-operative recurrent gastric cancer （n = 1） in the study, The oral contrast-enhanced ultrasonography （CEUS） imaging of the stomach clearly demonstrated the anatomy of the stomach and morphologic features of gastric lesions, With optimal scanning window and imaging display under oral CEUS, intravenous CEUS clearly showed the perfusion of gastric lesions with various characteristic manifestations. Both 2D and 3D DCUS images clearly demonstrated normal gastric wall as a three-layer structure, from the inside out, hypere- choic mucosa, hypoechoic muscularis and hyperechoic serosa, respectively. There were statistical significant differences of AT （8.68±2.06 vs 10.43 ±2.75, P = 0.017）, PI （34.64 ± 6.63 vs 29.58 ± 8.22, P = 0.023） and EI （29.72 ± 6.69 vs 22.66 ± 7.01, P = 0.001） between malignant lesions and normal gastric wall. However, no differences of AT, PI and EI between benign lesions and normal gastric wall tissue were found. 3D DCUS could intuitively display morphological features and vascularities of the lesions with multiplanar and volume views. 3D DCUS imaging provided comprehen- sive information complementary to 2D imaging. The crater or wellhead appearances and feeding vessels as well as distorted nourishing vasculature of gastric carcinoma were better seen with 3D imaging than 2D imaging. CONCLUSION： DCUS imaging can simultaneouslydisplay the anatomic and perfusion features of gastric lesions. 3D DCUS can provide additional information to 2D DCUS for evaluation of gastric lesions.

Evolution of gastrointestinal double contrast radiography in China:researches,application and popularization

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Contrast-enhanced and targeted ultrasound

Ultrasonic imaging is becoming the most popular medical imaging modality,owing to the low price per examination and its safety.However,blood is a poor scatterer of ultrasound waves at clinical diagnostic transmit frequencies.For perfusion imaging,markers have been designed to enhance the contrast in B-mode imaging.These so-called ultrasound contrast agents consist of microscopically small gas bubbles encapsulated in biodegradable shells.In this review,the physical principles of ultrasound contrast agent microbubble behavior and their adjustment for drug delivery including sonoporation are described.Furthermore,an outline of clinical imaging applications of contrast-enhanced ultrasound is given.It is a challenging task to quantify and predict which bubble phenomenon occurs under which acoustic condition,and how these phenomena may be utilized in ultrasonic imaging.Aided by high-speed photography,our improved understanding of encapsulated microbubble behavior will lead to more sophisticated detection and delivery techniques.More sophisticated methods use quantitative approaches to measure the amount and the time course of bolus or reperfusion curves,and have shown great promise in revealing effective tumor responses to anti-angiogenic drugs in humans before tumor shrinkage occurs.These are beginning to be accepted into clinical practice.In the long term,targeted microbubbles for molecular imaging and eventually for directed anti-tumor therapy are expected to be tested.

Diagnosis of liver cirrhosis with contrast-enhanced ultrasound

The assessment of the extent of liver fibrosis is very important for the prognosis and clinical management of chronic liver diseases.Although liver biopsy is the gold standard for the assessment of liver fibrosis,new non-invasive diagnostic methods are urgently needed in clinical work due to certain limitations and complications of biopsy.Noninvasive imaging studies play an important role in the diagnosis of focal liver disease and diffuse liver diseases.Among them,ultrasonography is the first choice for study of the liver in clinical work.With the development of ultrasound contrast agents and contrast specific imaging techniques,contrastenhanced ultrasound(CEUS) shows good performance and great potential in the evaluation of liver fibrosis.Researchers have tried different kinds of contrast agent and imaging method,such as arrival time of contrast agent in the hepatic vein,and quantitative analysis of the enhancement level of liver parenchyma,to evaluate the degree of liver fibrosis during the past 10 years.This review mainly summarizes the clinical studies concerning the assessment of liver fibrosis using CEUS.

Effectiveness of contrast-enhanced harmonic endoscopic ultrasound for the evaluation of solid pancreatic masses

AIM:To evaluate the usefulness of contrast-enhanced harmonic endoscopic ultrasound(CH-EUS)in differentiating between pancreatic adenocarcinomas and other pancreatic disease.METHODS:This retrospective cohort study evaluated90 patients who were seen between November 2010and May 2013.All these patients had solid pancreatic masses that had a hypoechoic appearance on EUS.All patients underwent CH-EUS to evaluate this diagnostic method’s usefulness.The mass lesions observed on CH-EUS were classified into three categories based on their echo intensity:hypoenhanced,isoenhanced,and hyperenhanced lesions.We adjusted the sensitivity and the specificity of each category for detecting malignancies.We also estimated the accuracy of CH-EUS by comparing it to a pathological diagnosis.RESULTS:Of the 90 patients,62 had a pancreatic adenocarcinoma.Fifty-seven out of 62 pancreatic adenocarcinomas showed a hypoenhanced pattern on CHEUS.The sensitivity was 92%,the specificity 68%and the accuracy approximately 82%.The area under the curve of the receiver operating characteristic analysis for CH-EUS was 0.799.There is a significant association between the hypoenhanced pattern on CH-EUS and pancreatic duct adenocarcinoma(χ2=35.264,P<0.001).In pathological examinations,the number of specimens for EUS-fine needle aspiration(EUS-FNA)was considered insufficient for diagnosis in three patients,and in two patients,the results were reported to be negative for malignancy.Pancreatic masses in all five patients revealed a hypoenhanced pattern with CH-EUS.Three patients were diagnosed with pancreatic adenocarcinoma based on the pathology results of a biopsy,and the remaining two patients were clinically diagnosed with malignancy.CONCLUSION:CH-EUS is useful for distinguishing between pancreatic adenocarcinoma and other pancreatic disease.When a pancreatic mass shows a hypoenhanced pattern on CH-EUS but involves either insufficient samples or negative results with EUS-FNA,clinicians might consider performing another pathologic diagnosis on the basis of an EUS-FNA sample or a biopsy.

Contrast-enhanced endoscopic ultrasonography

Contrast agents are increasingly being used to characterize the vasculature in an organ of interest,to better delineate benign from malignant pathology and to aid in staging and directing therapeutic procedures.We review the mechanisms of action of first,second and third generation contrast agents and their use in various endoscopic procedures in the gastrointestinal tract.Various applications of contrast-enhanced endoscopic ultrasonography include differentiating benign from malignant mediastinal lymphadenopathy,assessment of depth of invasion of esophageal,gastric and gall bladder cancers and visualization of the portal venous system and esophageal varices.In addition,contrast agents can be used to differentiate pancreatic lesions.The use of color Doppler further increases the ability to diagnose and differentiate various pancreatic malignancies.The sensitivity of power Doppler sonography to depict tumor neovascularization can be increased by contrast agents.Contrast-enhanced harmonic imaging is a useful aid in identifying the tumor vasculature and studying pancreatic microperfusion.In the future,these techniques could potentially be used to quantify tumor perfusion,to assess and monitor the efficacy of antiangiogenic agents,to assist targeted drug delivery and allow molecular imaging.

Evaluation of Carotid Atherosclerotic Plaque Stability with Contrast-enhanced Ultrasonography

This study was aimed to evaluate the relationship between carotid atherosclerotic plaque stability and the clinical symptoms in patients with carotid atherosclerotic plaques by using contrast-enhanced ultrasonography. Fifty patients with carotid atherosclerotic plaques were enrolled and examined with contrast-enhanced ultrasonography. The correlation of contrast agent enhancement of the carotid atherosclerotic plaques and the clinical symptoms was analyzed. The results showed that among the 50 patients, plaques were enhanced in the 23 patients with obvious clinical symptoms. In 27 patients without apparent clinical symptoms, plaques were enhanced sparsely in 15 patients and not enhanced in 12 patients. It was suggested that contrast-enhanced ultrasonography could be used for the examination of the microcirculation in carotid atherosclerotic plaques on real-time basis and serve as a new noninvasive approach for the assessment of stability of carotid atherosclerotic plaques.

Effect of fatty liver background on contrast-enhanced ultrasonographic appearance of focal nodular hyperplasia

BACKGROUND: Focal nodular hyperplasia (FNH) is increasingly diagnosed as a result of the advances in imaging studies such as contrast-enhanced ultrasonography (CEUS), enhanced computed tomography and magnetic resonance imaging. However, FNH with atypical features can be difficult to differentiate from other benign and malignant tumors. The aim of this study was to investigate the influence of fatty liver background on the CEUS characteristics of FNH. METHODS: Twenty-six patients with FNH were divided into two groups: group A included 14 patients with fatty liver and group B included 12 patients with normal liver background. Conventional two-dimensional ultrasonography and color Doppler flow imaging (CDFI) were conducted and followed by real-time dual-frame CEUS. RESULTS: On two-dimensional ultrasonography, hypoechoic nodules were present in most of the patients in group A (12/14) and hyperechoic nodules in most of those in group B (7/12). The difference in the nodule echotextures between the two groups was statistically significant (P<0.05). Nodules with centrifugal blood flow signals on CDFI were found in 6 of the 14 patients in group A and 5 of the 12 in group B (P>0.05). On CEUS, nodules with a central spoked-wheel-like enhancement pattern in the early arterial phase were observed in 8 patients in group A and those with an eccentric enhancement pattern in the remaining 6 patients. In this group, 3 patients had hypoechoic nodules in the delayed phase. Eleven of the 14 patients in this group were diagnosed accurately with CEUS. In group B, nodules with a rapid central spoked-wheel-like enhancement pattern in the early arterial phase were found in 8 patients by CEUS and those with rapid an eccentric enhancement pattern in 4. The nodules were found to be continuously enhanced in the delayed phase. All of the patients in group B were accurately diagnosed with CEUS. CONCLUSIONS: A FNH nodule on a background of fatty liver may present a hypoechoic pattern on two-dimensional ultrasonography and a hypoechoic wash-out pattern in the delayed phase on CEUS. At this time, punch biopsy is needed for the diagnosis or differential diagnosis of FNH.