Computed Tomography for the Diagnosis of Intraperitoneal Infected Fluid Collections after Surgery for Gastric Cancer. Role of Texture Analysis.

BACKGROUND AND AIMS: Several computed tomographic (CT) imaging features have been proposed to describe the infection of postoperative abdominal fluid collections; however, these features are vague, and there is a significant overlap between infected and non-infected collections. We assessed the role of textural parameters as additional diagnostic tools for distinguishing between infected and non-infected peritoneal collections in patients operated for gastric cancer. METHODS: From 527 patients operated for gastric cancer, we retrospectively selected 82 cases with intraperitoneal collections who underwent CT exams. The fluid component was analyzed through a novel method (texture analysis); different patterns of pixel intensity and distribution were extracted and processed through a dedicated software (MaZda). A univariate analysis comparing the parameters of texture analysis between the two groups was performed. Afterwards, a multivariate analysis was performed for the univariate statistically significant parameters. RESULTS: The study included 82 patients with bacteriologically verified infected (n=40) and noninfected (n=42) intraperitoneal effusions. The univariate analysis evidenced statistically significant differences between all the parameters involved. The multivariate analysis highlighted 10 parameters as being statistically significant, adjusted to Bonferroni correction. CONCLUSIONS: Our evidence supports the fact that textural analysis can be used as a complementary diagnostic tool for the detection of infected fluid collections after gastric cancer surgery. Further studies are required to validate the accuracy of this method.

Role of computer tomography and endoscopic ultrasonography in assessing portal and superior mesenteric vessels invasion in cephalo-pancreatic adenocarcinoma.

AIM: The aim of this study is to evaluate the information given by contrast-enhanced computer tomography (CECT) and ultrasound endoscopy (EUS) regarding vascular involvement of cephalo-pancreatic cancer, data compared with intraoperative findings. MATERIAL AND METHODS: We choose to analyze the most often interested vessels by tumor development, such as superior mesenteric artery (SMA), superior mesenteric vein (SMV) and portal vein (PV). The patients included in the study (n=425) had a cephalo-pancreatic tumor diagnosed in our Institute and a positive histology for pancreatic adenocarcinoma. The exclusion criteria were: tumors in sites other than the head of the pancreas (including metastases); tumor involvement of common hepatic artery, celiac trunk, inferior cava vein or aorta; CECT or EUS diagnosis performed in another center; and a delay of more than 35 days between the diagnostic imaging and surgery. RESULTS: In diagnosing SMA invasion CECT had an accuracy of 84,92% and EUS had an accuracy of 87,39%. In diagnosing PV and SMV involvement, CECT had an accuracy of 84,83% and EUS had an accuracy of 92,17%. The accuracy of the two combined examinations in diagnosing vascular invasion was 93%. CONCLUSONS: Both types of examination have showed good accuracies in diagnosing vascular invasion separately. A combination of the two may be used when the CECT result is uncertain as it provides a higher chance of a correct diagnosis. KEY WORDS: Pancreatic cancer, Resectability criteria, Vascular invasion.

Contrast enhanced harmonic ultrasonography for the evaluation of acute scrotal pathology. A pictorial essay.

Conventional ultrasonographic evaluation (grey scale and Doppler) represents the first line investigation in the acute pathology of the scrotum. Its diagnosis value in acute scrotal pathology is undoubted in regard with hypervascular lesions, but in the evaluation of isoechoic and hypo/avascular lesions i.v. contrast-enhanced harmonic ultrasonography (CEUS) is recommended in establishing a firm and certain diagnosis. Besides these, CEUS has an important role in the evaluation of the remaining viable testicular tissue in cases of testicular trauma, thus guiding a limited excision surgery. This paper aims to discuss the added diagnosis value of CEUS and to illustrate this through various ultrasonographic images suggestive for acute scrotum pathology.

Intracavitary applications of ultrasound contrast agents in hepatogastroenterology.

The era of the real time low mechanical index (MI) contrast enhanced ultrasound (CEUS) began in 2004. Since then, CEUS with second generation contrast agents like SonoVue has been able to offer a new clinical utility both in diagnosis and in interventional therapies. Intracavitary administration of SonoVue is an off-label, extravascular application of CEUS. There are two distinct applications in gastroenterology that are currently emerging: contrast agent injection into physiological cavities and injection into non-physiological cavities and fistulas. Numerous reports on the extravascular or intracavitary administration of SonoVue have been published and the results are positive, even though larger prospective studies are still lacking.

Contrast enhanced ultrasound and computer tomography diagnosis of solid and mixed pancreatic tumors - analysis of confounders.

AIMS. The aim of this study was to evaluate the leading causes of discrepancies between imaging studies [contrast enhanced ultrasound (CEUS) and contrast enhanced computer tomography (CECT)] diagnosis and histology in patients presenting to a tertiary referral center with previously detected pancreatic masses by standard abdominal ultrasound. METHODS. We performed a prospective longitudinal observational study on 76 patients with pancreatic masses: 57 (75%) patients with solid pancreatic tumors and 19 (25%) patients with cystic and mixed pancreatic masses. For each tumor the CEUS and CECT features were analyzed and compared with the final histological diagnosis. RESULTS. Testing the performance of CEUS and CECT in evaluating the benign or malignant etiology of pancreatic masses, we obtained a probability of 82% for CEUS and of 83% for CECT, for a randomly selected individual from the pancreatic tumor group to have an imaging result indicating suspicion for malignancy. We obtained discordances with the histopathological diagnosis in 25 (32.89%) patients for CEUS and in 23 (30.26%) patients for CECT. In multiple regression analysis, two variables independently influenced the discordance between the two imaging methods and histological conclusion: enhancement pattern and tumor nature (solid vs. cystic). CONCLUSIONS.CEUS and CECT showed a good diagnostic performance in differentiating benign from malignant pancreatic tumors. Enhancement pattern and tumor nature (solid vs. cystic) are independent confounders between imaging and histological diagnosis.

Added value of intravenous contrast-enhanced ultrasound for characterization of cystic pancreatic masses: a prospective study on 37 patients.

UNLABELLED: The aim of this study was to evaluate the added value of contrast-enhanced ultrasound (CEUS) in the pancreatic cystic mass (PCM) diagnosis by using a qualitative and quantitative analysis in order to make a relevant characterization. PATIENTS AND METHOD: Between December 2008 and November 2011, 37 patients with PCM discovered at ultrasound examination were prospectively followed. A qualitative and quantitative CEUS analysis was performed in order to differentiate etiologies of the PCM. In the quantitative analysis several parameters were followed: Peak Intensity (PI), Time to Peak (TTP), maximum ascending gradient (GRAD), Time to maximum gradient (TTG) and Area Under the Curve (AUC). Normalized ratios were also calculated. In all patients a definite cytological or histological diagnosis was obtained. RESULTS: Thirty-seven patients were studied: 12 with pancreatitis-associated pseudocyst and 25 with cystic tumors (10 serous cystic adenoma, 5 mucinous cystic adenoma, 6 cystadenocarcinomas, 2 solid pseudopapillary tumors and 2 intraductal papillary mucinous neoplasms). There was a significant difference of the nAUC and nTTP between pseudocyst and cystic tumors, p=0.03 and p=0.01, respectively. A normalized TTP value above 7 sec was suggestive for the diagnosis of pseudocysts with 79.16 % accuracy. There was a significant difference of nTTP and nTTG between the benign and malignant lesions. nTTP < 9 sec and nTTG < 8.5 sec rules out malignant cysts in almost 90% of cases. CONCLUSION: The CEUS is useful in the diagnosis of PCM. The quantitative analysis of the enhancement of the cystic wall may discriminate the different types of the PCM.

Ultrasonography contribution to the detection and characterization of hepatic restructuring: is the "virtual biopsy" taken into consideration?

Generally, the evolution of diffuse liver diseases is variable but quite long. Even the severe types of chronic hepatitis have a slow progression which implies decades, often over 20-30 years. Cirrhosis is the principal long time complication of chronic hepatopathies. It represents a major risk factor for the development of hepatocellular carcinoma. Ultrasonography plays an important role among the methods used for detecting diffuse liver diseases, for placing them and identifying supplementary risk factors for carcinogenesis and of hepatocellular carcinoma itself. The two- and especially the three-dimensional exploration allow the characterization of hepatic texture and the identification of certain changes which may suggest hepatic restructuring.