Application of Contrast-Enhanced Ultrasound in Cystic Pancreatic Lesions Using a Simplified Classification Diagnostic Criterion. Biomed Res Int. 2015;2015:974621. [PMID: 26090467 PMCID: PMC4450338 DOI: 10.1155/2015/974621]

Can cereal-based oral contrast agents-assisted ultrasound become an alternative to non-contrast magnetic resonance imaging (MRI) in radiological follow-up for pancreatic cystic lesions?

BACKGROUND

Pancreatic cystic lesions (PCLs) are recommended to be examined by magnetic resonance imaging (MRI), yet MRI still has limitations, such as high costs, the risk of triggering claustrophobia, and relatively low availability compared with ultrasound. Oral contrast agents-assisted ultrasound has been used to examine the gallbladder and stomach, but whether oral contrast agents could improve the accuracy of transabdominal ultrasound (TAUS) for PCLs and could be a potential alternative to non-contrast MRI for PCL follow-up has not been studied. This study aimed to explore the value of cereal-based oral contrast agents in improving the accuracy of PCLs during TAUS.

METHODS

This is a prospective cohort study. Patients with PCL who were admitted to our center between January 2023 and January 2024 were enrolled, and TAUS was performed before and after taking cereal-based oral contrast agents. The imaging quality of the PCL was measured by structural visualization scores. The structural visualization scores of oral contrast agent-assisted ultrasound and non-contrast MRI were also compared.

RESULTS

A total of 27 patients with PCLs were enrolled, and 30 PCLs were detected. The sonolucency of the PCL improved after oral contrast agent administration. Before taking the agent, only 30% of patients had satisfactory sonolucency; after taking the oral contrast agent, the corresponding proportion reached 80% (P=0.002). The structural visualization score of the PCL determined by oral contrast agent-assisted TAUS was higher than that determined without the aid of an agent [1 (0-6) vs. 1 (0-3), P=0.001], which was mainly reflected in the increase in the number of visible septa after taking the agent. No significant difference was detected between the structural visualization score of the PCL examined by oral contrast agent-assisted TAUS and that examined by non-contrast MRI and the correlation between the 2 types of scores were satisfactory [1 (0-6) vs. 2 (0-7), P=0.070, Spearman correlation factor r=0.880].

CONCLUSIONS

This study used a structured scoring system to confirm that cereal-based oral contrast agents could improve the ultrasound quality of PCLs, and the correlation between the quality of oral contrast agent-assisted ultrasound and non-contrast MRI findings on PCLs was satisfactory. Further research to improve visualization of PCLs on TAUS using oral contrast agents could result in TAUS being a potential alternative to MRI in the follow-up of PCLs in resource-limited situations.

Radiomics Based on Contrast-Enhanced Ultrasound Images for Diagnosis of Pancreatic Serous Cystadenoma

OBJECTIVE

The purpose of the study was to develop and validate a radiomics model by using contrast-enhanced ultrasound (CEUS) data for pre-operative differential diagnosis of pancreatic cystic neoplasms (PCNs), especially pancreatic serous cystadenoma (SCA).

METHODS

Patients with pathologically confirmed PCNs who underwent CEUS examination at Chinese PLA hospital from May 2015 to August 2022 were retrospectively collected. Radiomic features were extracted from the regions of interest, which were obtained based on CEUS images. A support vector machine algorithm was used to construct a radiomics model. Moreover, based on the CEUS image features, the CEUS and the combined models were constructed using logistic regression. The performance and clinical utility of the optimal model were evaluated by area under the receiver operating characteristic curve (AUC), sensitivity, specificity and decision curve analysis.

RESULTS

A total of 113 patients were randomly split into the training (n = 79) and test cohorts (n = 34). These patients were pathologically diagnosed with SCA, mucinous cystadenoma, intraductal papillary mucinous neoplasm and solid-pseudopapillary tumor. The radiomics model achieved an AUC of 0.875 and 0.862 in the training and test cohorts, respectively. The sensitivity and specificity of the radiomics model were 81.5% and 86.5% in the training cohort and 81.8% and 91.3% in the test cohort, respectively, which were higher than or comparable with that of the CEUS model and the combined model.

CONCLUSION

The radiomics model based on CEUS images had a favorable differential diagnostic performance in distinguishing SCA from other PCNs, which may be beneficial for the exploration of personalized management strategies.

Contrast-enhanced US of the Liver and Kidney: A Problem-solving Modality

Contrast-enhanced US (CEUS) has an important role as a supplement to CT or MRI in clinical practice. The main established utilizations are in the liver and the kidney. The primary advantages of CEUS compared with contrast-enhanced CT or MRI relate to its superior contrast resolution, real-time continuous scanning, pure intravascular nature, portability, and safety-especially in patients with renal impairment or CT or MRI contrast agent allergy. This article focuses on the use of CEUS in the liver and kidney.

Contrast-enhanced ultrasound of the spleen, pancreas and gallbladder in children

Gray-scale and color/power Doppler ultrasound (US) are the first-line imaging modalities to evaluate the spleen, gallbladder and pancreas in children. The increasing use of contrast-enhanced ultrasound (CEUS) as a reliable and safe method to evaluate liver lesions in the pediatric population promises potential for imaging other internal organs. Although CEUS applications of the spleen, gallbladder and pancreas have been well described in adults, they have not been fully explored in children. In this manuscript, we present an overview of the applications of CEUS for normal variants and diseases affecting the spleen, gallbladder and pancreas. We highlight a variety of cases as examples of how CEUS can serve in the diagnosis and follow-up for such diseases in children. Our discussion includes specific examination techniques; presentation of the main imaging findings in various benign and malignant lesions of the spleen, gallbladder and pancreas in children; and acknowledgment of the limitations of CEUS for these organs.

Diagnostic Yield of Transabdominal Ultrasonography for Evaluation of Pancreatic Cystic Lesions Compared with Endoscopic Ultrasonography

Detection rates of pancreatic cystic lesions (PCLs) have increased, resulting in greater requirements for regular monitoring using imaging modalities. We aimed to evaluate the capability of ultrasonography (US) for morphological characterization of PCLs as a reference standard using endoscopic ultrasonography (EUS). A retrospective analysis was conducted of 102 PCLs from 92 patients who underwent US immediately prior to EUS between January 2014 and May 2017. The intermodality reliability and agreement of the PCL morphologic findings of the two techniques were analyzed and compared using the intraclass correlation coefficient and κ values. The success rates of US for delineating PCLs in the head, body, and tail of the pancreas were 77.8%, 91.8%, and 70.6%, respectively. The intraclass correlation coefficient for US and the corresponding EUS lesion size showed very good reliability (0.978; p < 0.001). The κ value between modalities was 0.882 for pancreatic duct dilation, indicating good agreement. The κ values for solid components and cystic wall and septal thickening were 0.481 and 0.395, respectively, indicating moderate agreement. US may be useful for monitoring PCL growth and changes in pancreatic duct dilation, but it has limited use in the diagnosis and surveillance of mural nodules or cystic wall thickness changes.

Cystic pancreatic lesions, the endless dilemma

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic lesions. The proper diagnosis, differentiation, and staging of these cystic lesions are considered a crucial issue in planning further management. There are great challenges for their diagnostic models. In our time, new emerging methods for this diagnosis have been discovered. Endoscopic ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needle-based confocal laser endomicroscopy, through the needle microforceps biopsy, and single-operator cholangioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic lesions. Hereby we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

Transabdominal Ultrasound for Follow-Up of Incidentally Detected Low-Risk Pancreatic Cysts: A Prospective Multicenter Study

OBJECTIVE. The purpose of this study is to investigate the detection rate of transabdominal ultrasound (TAUS) for pancreatic cysts incidentally detected on CT or MRI as well as the factors that influence detection rates. SUBJECTS AND METHODS. Fifty-seven patients with low-risk pancreatic cysts (n = 77; cyst size, 5 mm to 3 cm) that were incidentally detected on CT or MRI were prospectively enrolled at five institutions. At each institution, TAUS was independently performed by two radiologists who assessed detection of cysts, cyst location and size, and the diameter of the main pancreatic duct (MPD). Cyst detection rates based on cyst size, location, and multiplicity and the body mass index of the patient were compared using the Mann-Whitney test. Kappa statistics and the interclass correlation coefficient were used to evaluate interobserver agreement regarding cyst detection and consistency of cyst size and the diameter of the MPD on TAUS versus prior CT or MRI. RESULTS. The detection rate for known low-risk pancreatic cysts was 81.8% (63/77) and 83.1% (64/77) for TAUS conducted by each of the two radiologists. The detection rate for larger (≥ 10 mm) cysts was significantly higher than that for smaller cysts (89.0% vs 63.6% for TAUS performed and interpreted by radiologist 1 [TAUS 1] and 89.0% vs 68.2% for TAUS conducted and interpreted by radiologist 2 [TAUS 2]; p < .05). A higher detection rate was noted for cysts located outside the tail of the pancreas compared with those located in the tail (89.5% vs 65.0% for TAUS 2; p = .01), and the detection rate was also significantly higher for single cysts than for multiple cysts (90.9% vs 69.7% for TAUS 1; p = .02). However, no significant difference was observed for body mass index. Interobserver agreement was excellent regarding the size of the detected cysts (inter-class correlation coefficient: 0.964 [95% CI, 0.940-0.979] for CT, TAUS 1, and TAUS 2 and 0.965 [95% CI. 0.924-986] for MRI, TAUS 1, and TAUS 2) and the diameter of the MPD (interclass correlation coefficient, 0.934; 95% CI, 0.898-0.959). CONCLUSION. TAUS could be a useful alternative imaging tool for surveillance of known low-risk pancreatic cysts, especially single pancreatic cysts and those that are of larger size (≥ 1 cm) or are located outside the tail.

Focal Pancreatic Lesions: Role of Contrast-Enhanced Ultrasonography

The introduction of contrast-enhanced ultrasonography (CEUS) has led to a significant improvement in the diagnostic accuracy of ultrasound in the characterization of a pancreatic mass. CEUS, by using a blood pool contrast agent, can provide dynamic information concerning macro- and micro-circulation of focal lesions and of normal parenchyma, without the use of ionizing radiation. On the basis of personal experience and literature data, the purpose of this article is to describe and discuss CEUS imaging findings of the main solid and cystic pancreatic lesions with varying prevalence.

Intraductal papillary mucinous neoplasm (IPMN) of the pancreas: recommendations for Standardized Imaging and Reporting from the Society of Abdominal Radiology IPMN disease focused panel

There have been many publications detailing imaging features of malignant transformation of intraductal papillary mucinous neoplasms (IPMN), management and recommendations for imaging follow-up of diagnosed or presumed IPMN. However, there is no consensus on several practical aspects of imaging IPMN that could serve as a clinical guide for radiologists and enable future data mining for research. These aspects include how to measure IPMN, define reporting terminology, standardize reporting and unify guidelines for surveillance. The Society of Abdominal Radiology (SAR) created multiple Disease-Focused Panels (DFP) comprised multidisciplinary panel members who focus on a particular disease, with the goal to develop ways for radiologists to improve patient care, education, and research. DFP members met to identify the current controversies and limitations of imaging pancreatic IPMN. This paper aims to provide a practical review of the key imaging characteristics of IPMN for trainees and practicing radiologists, to guide uniformity of performance and interpretation of surveillance imaging studies, and to improve communication with clinicians by providing a lexicon and reporting template based on the experience of the SAR-DFP panel members.

Update in Contrast-Enhanced Ultrasound

BACKGROUND

The aim of modern medicine is to safely classify diseases for successful therapy without invasive measures. Sonography, computed tomography (CT), and magnetic resonance imaging (MRI) are potent imaging techniques. However, without contrast medium, the informative value of the 3 native methods is limited. The advantages of sonography are: no radiation exposure or previously known physically harmful interactions with tissue, proportionate disappearance of a contrast agent risk, no (probably irreversible) contrast agent deposits, and no risk of renal insufficiency. But, is that enough to compete with of even exceed CT and MRI?

SUMMARY

In this review, the state of the art of contrast-enhanced ultrasound (CEUS) in the abdominal cavity is presented. The remarkable diagnostic possibilities can unfortunately only be demonstrated here in a small number of impressive, typical case studies underpinned by the literature, so that, from one's own perspective, the full spectrum of CEUS can be used by oneself or initiated. Within the limits of physics, the real-time dynamics of CEUS enable conclusions to be drawn, so that with the current technology, sonography, including expansion by contrast, can be considered superior to other imaging methods. It is not uncommon for CEUS to have the value of a control and reference method.

KEY MESSAGES

Sonography very often enables reliable diagnostics. The introduction of a contrast agent in sonography has led to a quantum leap similar to that of other imaging techniques. Already natively, the real-time representation of dynamic events leads to a certain superiority, i.e., complete observation of the inflow and outflow phases of the contrast medium and the resulting diagnostic; tissue-specific differentiation options provide a unique selling point. Further advantages of the first-choice imaging diagnostic method are: a lack of radiation exposure, repeatability of the examination at any time, local independence, a negligible allergy rate compared to the contrast agents of other methods, and a lack of kidney and thyroid exposure or excluded deposits.

Comparative Diagnostic Evaluation with Contrast-Enhanced Ultrasound, Computed Tomography and Magnetic Resonance Imaging in Patients with Pancreatic Cystic Neoplasms

Purpose

The purpose of our study was to evaluate the role of contrast-enhanced ultrasound (CEUS) with magnetic resonance imaging (MRI) and computed tomography (CT) in the pathological diagnosis of pancreatic cystic neoplasms (PCNs).

Methods

A total of 90 patients (66 women, 24 men) aged 18–71 years were studied prospectively. CEUS was performed in all patients, whereas MRI was performed in 85 patients and CT in 69 patients. We analyzed the sensitivity and accuracy of these three imaging modalities to diagnose the PCNs. Neoplasm size, location, shape, intralesional mural nodules, septa and duct dilatation were also assessed by different radiologists.

Results

There were no significant differences in sensitivity for discriminating PCNs from pancreatic cystic lesions between CEUS and MRI (p=0.614) or between CEUS and CT (p=0.479). The diagnostic accuracy of CEUS for classifying PCNs was 64.4% (58/90), which was higher than that of CT (53.6%, 37/69, P=0.017), and lower than that of MRI (70.6%, 60/85, p=0.791). Regarding tumor size for lesions larger than 3 cm, CEUS was superior to CT in differentiating the specific type of PCN (p=0.041), and CEUS had the same value as MRI (p=0.774). Furthermore, CEUS is valuable for precisely characterizing internal structures, for instance, septa (p=0.003, compared with CT; p=0.443, compared with MRI) and nodules (p= 0.018, compared with CT; p=0.033, compared with MRI). The number of septa (p=0.033) and cyst morphology (p=0.016) were meaningful indicators in differentiating serous and mucinous adenoma. There was no significant difference in evaluating size and detecting duct dilatation among the three imaging methods.

Conclusion

CEUS compares favorably with MRI in displaying the inner structure of PCNs and offers advantages over CT. CEUS can contribute in an important way to the diagnosis of pancreatic cystic neoplasms.

The Value of Contrast-Enhanced Ultrasound Classification in Diagnosis of Pancreatic Cystic Lesions

Objective

To compare the consistency of contrast-enhanced ultrasound (CEUS) classification results with magnetic resonance imaging (MRI) and to investigate the diagnostic value of CEUS classification in pancreatic cystic lesions.

Methods

84 cases of pancreatic cystic lesions were enrolled in this study. According to the CEUS classification methods of previous study in our center, all the lesions were classified into four types: type I, unilocular cysts; type II, microcystic lesions; type III, macrocystic lesions; and type IV, cystic lesions with enhanced solid components. The consistency of CEUS and MRI typing results was analysed. Among the 84 cases, 45 cases had pathological results. The CEUS results were compared with the pathological results, and the diagnostic value of CEUS classification in diagnosing pancreatic cystic lesions was explored.

Results

Among the 84 cases, CEUS diagnosed 8 cases of type I, 24 of type II, 8 of type III, and 45 of type IV. MRI diagnosed 10 cases of type I, 25 of type II, 7 of type III, and 43 of type IV. The classification typing results of CEUS were highly consistent with that of enhanced MRI (kappa value: 0.852). Among the 45 cases with pathological results, the diagnostic accuracy of each type was 91.1%, 95.6%, 93.3%, and 88.9%. The accuracy of CEUS and MRI in diagnosing pancreatic cystic lesions was 75.56% (34/45) and 80% (36/45), respectively. The diagnostic accuracy of CEUS had no significant difference from that of MRI (P=0.687).

Conclusion

The classification results by CEUS and MRI are in excellent agreement. The classification of pancreatic cystic lesions by CEUS is significantly helpful for clinical diagnosis.

Clinical use of contrast-enhanced ultrasound beyond the liver: a focus on renal, splenic, and pancreatic applications

Contrast-enhanced ultrasound (CEUS) is a relatively novel, but increasingly used, diagnostic imaging modality. In recent years, due to its safety, quickness, and repeatability, several studies have demonstrated the accuracy, specificity, and sensitivity of CEUS. The European Federation of Societies for Ultrasound in Medicine and Biology has recently updated the previous guidelines from 2012 for the use of CEUS in non-hepatic applications. This review deals with the clinical use and applications of CEUS for the evaluation of non-hepatic abdominal organs, focusing on renal, splenic, and pancreatic applications.

Periostin promotes tumor angiogenesis in pancreatic cancer via Erk/VEGF signaling

Pancreatic cancer (PaC) consists of a bulk of stroma cells which contribute to tumor progression by releasing angiogenic factors. Recent studies have found that periostin (POSTN) is closely associate with the metastatic potential and prognosis of PaC. The purpose of this study is to determine the role of POSTN in tumor angiogenesis and explore the precise mechanisms. In this study, we used lentiviral shRNA and human recombinant POSTN protein (rPOSTN) to negatively and positively regulate POSTN expression in vitro. We found that increased POSTN expression promoted the tubule formation dependent on human umbilical vein endothelial cells (HUVECs). Moreover, knockdown of POSTN in PaC cells reduced tumor growth and VEGF expression in vivo. In accordance with these observations, we found that Erk phosphorylation and its downstream VEGF expression were upregulated achieved in rPOSTN-treated groups, opposing results were obversed in POSTN-slienced group. Meanwhile, Erk inhibitor SCH772984 significantly decreased VEGF expression as well as tubule formation of HUVECs in rPOSTN-treated PaC cells. Taken together, these findings suggest that POSTN promotes tumor angiogenesis via Erk/VEGF signaling in PaC and POSTN may be a new target for cancer anti-vascular treatment.

A new combined criterion to better predict malignant lesions in patients with pancreatic cystic neoplasms

Objective:

Cystic lesions of the pancreas have been increasingly recognized. Some lesions exhibit benign behavior, while others have unequivocal malignant potential. Thus, accurate identification of malignancy in patients diagnosed with pancreatic cystic neoplasms (PCNs) remains a major challenge. The aim of this study was to define a combined criterion to better predict malignant lesions in patients with PCNs.

Methods:

We retrospectively analyzed 165 patients who underwent resection of PCNs from October 2011 to May 2017. The relationship among malignancy and serum carbohydrate antigen 19-9 (CA19-9), preoperative neutrophil-to-lymphocyte ratio (NLR), and the presence of enhanced solid component on imaging was analyzed.

Results:

NLR before surgery in patients with malignant PCNs (2.81±2.14) was significantly higher than that in patients diagnosed with pancreatic neuroendocrine tumor (1.90±0.69, P=0.013) or healthy volunteers (1.40±0.48; P<0.001). Serum CA19-9 ≥39 U/mL, NLR >1.976 and presence of enhanced solid component were independent predictors of PCN malignancy. A combined criterion meeting any two or more of the three elements including CA19-9 ≥39 U/mL, NLR >1.976, and presence of enhanced solid component on computed tomography imaging is an indicator with a high positive predictive value of 80.5% and a high negative predictive value of 87.9%, and thus, represents a highly accurate test (86.1%).

Conclusions:

The new combined criterion is an effective predictor of tumor malignancy in patients with PCNs.

Imaging modalities for characterising focal pancreatic lesions

BACKGROUND

Increasing numbers of incidental pancreatic lesions are being detected each year. Accurate characterisation of pancreatic lesions into benign, precancerous, and cancer masses is crucial in deciding whether to use treatment or surveillance. Distinguishing benign lesions from precancerous and cancerous lesions can prevent patients from undergoing unnecessary major surgery. Despite the importance of accurately classifying pancreatic lesions, there is no clear algorithm for management of focal pancreatic lesions.

OBJECTIVES

To determine and compare the diagnostic accuracy of various imaging modalities in detecting cancerous and precancerous lesions in people with focal pancreatic lesions.

SEARCH METHODS

We searched the CENTRAL, MEDLINE, Embase, and Science Citation Index until 19 July 2016. We searched the references of included studies to identify further studies. We did not restrict studies based on language or publication status, or whether data were collected prospectively or retrospectively.

SELECTION CRITERIA

We planned to include studies reporting cross-sectional information on the index test (CT (computed tomography), MRI (magnetic resonance imaging), PET (positron emission tomography), EUS (endoscopic ultrasound), EUS elastography, and EUS-guided biopsy or FNA (fine-needle aspiration)) and reference standard (confirmation of the nature of the lesion was obtained by histopathological examination of the entire lesion by surgical excision, or histopathological examination for confirmation of precancer or cancer by biopsy and clinical follow-up of at least six months in people with negative index tests) in people with pancreatic lesions irrespective of language or publication status or whether the data were collected prospectively or retrospectively.

DATA COLLECTION AND ANALYSIS

Two review authors independently searched the references to identify relevant studies and extracted the data. We planned to use the bivariate analysis to calculate the summary sensitivity and specificity with their 95% confidence intervals and the hierarchical summary receiver operating characteristic (HSROC) to compare the tests and assess heterogeneity, but used simpler models (such as univariate random-effects model and univariate fixed-effect model) for combining studies when appropriate because of the sparse data. We were unable to compare the diagnostic performance of the tests using formal statistical methods because of sparse data.

MAIN RESULTS

We included 54 studies involving a total of 3,196 participants evaluating the diagnostic accuracy of various index tests. In these 54 studies, eight different target conditions were identified with different final diagnoses constituting benign, precancerous, and cancerous lesions. None of the studies was of high methodological quality. None of the comparisons in which single studies were included was of sufficiently high methodological quality to warrant highlighting of the results. For differentiation of cancerous lesions from benign or precancerous lesions, we identified only one study per index test. The second analysis, of studies differentiating cancerous versus benign lesions, provided three tests in which meta-analysis could be performed. The sensitivities and specificities for diagnosing cancer were: EUS-FNA: sensitivity 0.79 (95% confidence interval (CI) 0.07 to 1.00), specificity 1.00 (95% CI 0.91 to 1.00); EUS: sensitivity 0.95 (95% CI 0.84 to 0.99), specificity 0.53 (95% CI 0.31 to 0.74); PET: sensitivity 0.92 (95% CI 0.80 to 0.97), specificity 0.65 (95% CI 0.39 to 0.84). The third analysis, of studies differentiating precancerous or cancerous lesions from benign lesions, only provided one test (EUS-FNA) in which meta-analysis was performed. EUS-FNA had moderate sensitivity for diagnosing precancerous or cancerous lesions (sensitivity 0.73 (95% CI 0.01 to 1.00) and high specificity 0.94 (95% CI 0.15 to 1.00), the extremely wide confidence intervals reflecting the heterogeneity between the studies). The fourth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (dysplasia) provided three tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing invasive carcinoma were: CT: sensitivity 0.72 (95% CI 0.50 to 0.87), specificity 0.92 (95% CI 0.81 to 0.97); EUS: sensitivity 0.78 (95% CI 0.44 to 0.94), specificity 0.91 (95% CI 0.61 to 0.98); EUS-FNA: sensitivity 0.66 (95% CI 0.03 to 0.99), specificity 0.92 (95% CI 0.73 to 0.98). The fifth analysis, of studies differentiating cancerous (high-grade dysplasia or invasive carcinoma) versus precancerous (low- or intermediate-grade dysplasia) provided six tests in which meta-analysis was performed. The sensitivities and specificities for diagnosing cancer (high-grade dysplasia or invasive carcinoma) were: CT: sensitivity 0.87 (95% CI 0.00 to 1.00), specificity 0.96 (95% CI 0.00 to 1.00); EUS: sensitivity 0.86 (95% CI 0.74 to 0.92), specificity 0.91 (95% CI 0.83 to 0.96); EUS-FNA: sensitivity 0.47 (95% CI 0.24 to 0.70), specificity 0.91 (95% CI 0.32 to 1.00); EUS-FNA carcinoembryonic antigen 200 ng/mL: sensitivity 0.58 (95% CI 0.28 to 0.83), specificity 0.51 (95% CI 0.19 to 0.81); MRI: sensitivity 0.69 (95% CI 0.44 to 0.86), specificity 0.93 (95% CI 0.43 to 1.00); PET: sensitivity 0.90 (95% CI 0.79 to 0.96), specificity 0.94 (95% CI 0.81 to 0.99). The sixth analysis, of studies differentiating cancerous (invasive carcinoma) from precancerous (low-grade dysplasia) provided no tests in which meta-analysis was performed. The seventh analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) provided two tests in which meta-analysis was performed. The sensitivity and specificity for diagnosing cancer were: CT: sensitivity 0.83 (95% CI 0.68 to 0.92), specificity 0.83 (95% CI 0.64 to 0.93) and MRI: sensitivity 0.80 (95% CI 0.58 to 0.92), specificity 0.81 (95% CI 0.53 to 0.95), respectively. The eighth analysis, of studies differentiating precancerous or cancerous (intermediate- or high-grade dysplasia or invasive carcinoma) from precancerous (low-grade dysplasia) or benign lesions provided no test in which meta-analysis was performed.There were no major alterations in the subgroup analysis of cystic pancreatic focal lesions (42 studies; 2086 participants). None of the included studies evaluated EUS elastography or sequential testing.

AUTHORS' CONCLUSIONS

We were unable to arrive at any firm conclusions because of the differences in the way that study authors classified focal pancreatic lesions into cancerous, precancerous, and benign lesions; the inclusion of few studies with wide confidence intervals for each comparison; poor methodological quality in the studies; and heterogeneity in the estimates within comparisons.

Discrimination of serous cystadenoma from mucinous cystadenoma in the pancreas with contrast-enhanced ultrasonography: a prospective study in 61 patients

OBJECTIVES

The preoperative diagnosis between serous cystadenomas (SCAs) and mucinous cystadenomas (MCAs) in pancreas is significant due to their completely different biological behaviors. The purpose of our study was to examine and compare detailed contrast-enhanced ultrasonography (CEUS) images of SCAs and MCAs and to determine whether there are significant findings that can contribute to the discrimination between these two diseases.

METHODS

From April 2015 to June 2016, 61 patients (35 patients with SCAs and 26 patients with MCAs) were enrolled in this study. Forty-three cases were confirmed by surgical pathology and 18 by comprehensive clinical diagnoses. All of the CEUS characteristics of these lesions were recorded: size, location, echogenicity, shape, wall characteristics, septa characteristics, and the presence of a honeycomb pattern or nodules. CEUS examinations were performed by two ultrasound physicians.

RESULTS

Location (P=0.003), shape (P=0.000), thickness of the wall (P=0.005), the number of septa (P=0.001), and the honeycomb pattern (P=0.001) were statistically significantly different. A head-neck location, a lobulated shape, an inner regular honeycomb pattern, and a thin wall (<3 mm thick) were significant in diagnosing patients with SCAs. When two of these four findings were combined, we could achieve a sensitivity of 71.4% and a specificity of 80.8% to diagnose SCA; when three of these four findings were combined, the specificity was 100%. A body-tail location, a round/oval shape, 0-2 septa, and a thick wall (≥3 mm thick) were most often detected in patients with MCAs. When two of these four findings were combined, we could achieve a sensitivity of 88.5% and a specificity of 65.7% to diagnose MCA; when three of these four findings were combined, the area under the curve (Az) was highest at 0.832, with a sensitivity of 80.8% and a specificity of 85.7%.

CONCLUSIONS

The characteristics of tumor location, shape, thickness of the wall, the number of septa, and the honeycomb pattern by CEUS play an important role in the diagnosis of SCAs and MCAs. A combination of these findings can provide better diagnostic performance in the discrimination of SCAs from MCAs.