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Pancreatic multicenter ultrasound study (PAMUS)

AIM To describe the typical CEUS pattern of pancreatic lesions and to evaluate the diagnostic accuracy of Contrast-enhanced ultrasound (CEUS) in their characterization. MATERIALS AND METHODS All US and CEUS examinations of focal pancreatic masses performed in six centers during a period of five years were reviewed. Inclusion criteria were: focal pancreatic mass pathologically proved, visible at ultrasound (US) and studied with CEUS. All lesions were then evaluated for size, aspect and enhancement pattern. Sensitivity, specificity, positive and negative predictive values with 95% CIs were calculated to define diagnostic accuracy of CEUS in respect to pathology. Diagnostic confidence of US and CEUS, discerning between benign and malignant lesions, were represented by using ROC (receiver operating characteristics) curves. Agreement was evaluated by means of k statistics. RESULTS 1439 pancreatic lesions were included. At CEUS the lesions were divided into solid (89%) and cystic (12%) masses and classified into six and eight categories, respectively. Among the solid lesions, adenocarcinomas were characterized with an accuracy of 87.8%. Among the cystic lesions, cystic tumors were diagnosed with an accuracy of 97.1%. ROC curve area increased from 0.637 for US to 0.877 for CEUS (p<0.0001). Inter-observer agreement was slightly higher for solid (k=0.78) than cystic (k=0.62) lesions. In none of the centers side effects were reported. CONCLUSION CEUS is accurate in the characterization of pancreatic lesions. CEUS should be considered as a complementary imaging method for pancreatic lesions characterization.

Resectable Pancreatic Adenocarcinoma: Is the Enhancement Pattern at Contrast-Enhanced Ultrasonography a Pre-Operative Prognostic Factor?

The aim of our study was to determine whether the enhancement pattern of pancreatic adenocarcinoma at contrast-enhanced ultrasonography (CEUS) is related to patient prognosis after resection. CEUS of 42 resected adenocarcinomas were retrospectively reviewed. Tumors were divided into two groups: group A=poorly vascularized (presence of avascular areas) or group B=well vascularized (absence of avascular areas). All lesions were resected and underwent pathological examination assessing tumor differentiation as: undifferentiated (poorly differentiated) or differentiated (moderately and well differentiated). Mean vascular density (MVD) was also evaluated. CEUS enhancement and pathology were correlated (Spearmans test). Survival was analyzed with the Kaplan-Meier method. Multivariate analysis was performed with the Cox regression model. There were 30 differentiated and 12 undifferentiated adenocarcinomas at pathology. At CEUS, 10 lesions were poorly vascularized, whereas 32 lesions were well vascularized. Positive correlation was observed between CEUS groups and tumoral differentiation (rs=0.51; p=0.001) and between CEUS and MVD (rs=0.74; p<0.0001). Median survival in patients with group A vascularization at CEUS was significantly lower than in group B (p=0.015). Cox proportional hazard model revealed the presence of poorly vascularized tumor at CEUS (p=0.0001) as a predictor of higher mortality. In conclusion, CEUS enables accurate depiction of the vascularization of adenocarcinoma, with positive correlation to histology grade and MVD.

Contrast-enhanced ultrasound of the pancreas

The introduction of contrast-enhanced ultrasonography (CEUS) has led to major improvements in the diagnostic capabilities of ultrasound (US). The innovative use of CEUS for study of the pancreas has created the need for a definition of the most frequent dynamic features of solid and cystic masses. CEUS is less expensive compared to computed tomography and magnetic resonance imaging and is able to significantly improve the accuracy of US, allowing better characterization and staging of pancreatic pathologies.

Comparison between CT and CEUS in the diagnosis of pancreatic adenocarcinoma

PURPOSE The aim of this study is to compare CEUS and MDCT features of pancreatic ductal adenocarcinoma in relation to tumor size. MATERIALS AND METHODS All patients with pathological diagnosis of pancreatic adenocarcinoma and studied by means of CEUS and MDCT were enrolled in this study. Two radiologists evaluated tumor size, site and imaging appearance. Patients in which at least one method yielded a positive result were divided into 4 groups on the basis of lesion size. For each dimensional category, sensitivity of the two imaging methods was calculated and compared using McNemar test. RESULTS One hundred thirty-three patients were included in this study. In 9 of 133 patients neither MDCT nor US/CEUS could identify the lesion, while in 9 of 133 patients only MDCT and in 13 of 133 only US/CEUS could identify the lesion. In the remaining 102 patients, both MDCT and US/CEUS yielded a positive result. US/CEUS sensitivity was 86.47% while MDCT sensitivity was 83.58%, with no statistically significant difference (p = 0.523). For lesions smaller than 2 cm US/CEUS had a 100% sensitivity, while MDCT had a 73.33% sensitivity with no statistically significant difference (p = 0.125). For lesions between 2.1 and 3 cm US/CEUS had a sensitivity of 95.35%, while MDCT had a sensitivity of 83.72% with no statistically significant difference (p = 0.180). For lesions between 3.1 and 4 cm, US/CEUS had a sensitivity of 87.88%, while MDCT had a sensitivity of 93.94% with no statistically significant difference (p = 0.688). For lesions larger than 4 cm US/CEUS, had a sensitivity of 90.91%, while MDCT had a sensitivity of 100% with no statistically significant difference (p = 0.250). CONCLUSION US/CEUS sensitivity in diagnosing pancreatic ductal adenocarcinoma is adequate and does not statistically differ from that of MDCT. US/CEUS sensitivity seems to be higher for small and medium lesions, while MDCT sensitivity is higher for large lesions. By combining both the imaging methods a higher accuracy in diagnosing pancreatic ductal adenocarcinoma can be expected.

Focal pancreatic lesions: accuracy and complications of US-guided fine-needle aspiration cytology

Tissue confirmation of the diagnosis is required either for unresectable pancreatic masses or for resectable masses when the diagnosis is uncertain. In this article, we review indications, technique, and clinical results of percutaneous fine-needle aspiration of focal pancreatic lesions.

Brachial artery blood flow during submaximal isometric contraction of the biceps brachii and triceps brachii in humans: A preliminary observation

The purpose of this study was to evaluate brachial artery blood flow changes during submaximal isometric contraction of the biceps and triceps brachii, in order to clarify the influence of the upper arm muscles activity on the local arterial flow. The brachial artery blood flow velocity and diameter were evaluated in twenty healthy men (mean age 29.6 years) at baseline (resting position) and during submaximal isometric contraction of the biceps and triceps brachii by means of ultrasonography (B-MODE and Doppler ultrasound methods). The brachial artery blood flow velocity was significantly higher than resting position during submaximal isometric contraction of the biceps (P < 0.001) and triceps brachii (P = 0.019). As to the brachial artery diameter, no significant change was observed during submaximal isometric contractions of the biceps and triceps brachii. Our preliminary findings suggest that the brachial artery blood flow velocity similarly increases during submaximal isometric contraction of the biceps and triceps brachii.

Intraoperative ultrasonography of the pancreas

Intraoperative ultrasonography (IOUS) still remains a useful and occasionally a problem-solving technique in pancreatic diseases, even though its role has recently been downsized owing to preoperative imaging advances [1]. Since its introduction in the 1980s, progressive technical developments have led to an increase in the diagnostic accuracy of IOUS. The availability of scanners that provide the depiction of fine anatomic details and the detection of small lesions in real-time with excellent spatial and contrast resolution allow the widespread application of this imaging method [1, 2]. Moreover, IOUS is able to clearly show lesions not detectable with other preoperative imaging modalities, and to accurately define the extension of the tumor and its relationship with vessels, sometimes determining significant changes in the therapeutic management of patients [3]–[5]. In addition, its ability in guiding interventional procedures (i.e. biopsy, duct cannulation and drainage of abscesses or cysts) has been widely reported [2, 6]. Lastly, its impact has significantly increased since both the development of mini-invasive laparoscopic approaches, due to the impossibility for the surgeon to visually and manually inspect the affected organ and the retroperitoneum, and the recent introduction of alternative palliative treatments under IOUS-guidance [7, 8].