Interactive case discussion

Incidental lesions are frequently discovered during routine radiographic evaluations. Correlation with clinical history and additional confirmatory imaging is essential to the development of an accurate, focused differential diagnosis and for appropriate management. The objective of this presentation is to describe the imaging findings associated with incidentally found liver lesions and to review those clinical and radiologic features, which should be considered in development of an ordered and accurate differential diagnosis. Learning Objectives: 1. To introduce typical cases illustrating the role of imaging modalities in the differential diagnosis of unexpected liver lesion cases. 2. To motivate the audience by the use of voting pads to be involved in the diagnostic process. 3. To highlight the conclusion that may be drawn on the basis of the discussed cases

Analisi di dati acquisiti con OBS

2008/2009Gli OBS (Ocean Bottom Seismometer) sono ampiamente utilizzati negli studi sismici crostali attraverso l’utilizzo delle registrazioni di onde rifratte e riflesse a grande offset (Wide Angle Reflection/Refraction, WAR/R). L'analisi di questi dati comporta, solitamente, l'impiego di modellistica diretta e/o inversa al fine di giungere alle velocità dei singoli strati e alle profondità delle interfacce. In questa tesi, invece, si presenta un approccio diverso che prevede: 1) costruzione di modelli di velocità dall’analisi dei segnali rifratti; 2) elaborazione dei dati OBS al fine di ottenere immagini sismiche a riflessione. In particolare, gli OBS e gli scoppi sono stati riportati ad uno stesso datum (superficie del mare), utilizzando il Wave Equation Datuming (WED). Dopo il WED è stato possibile applicare l'elaborazione tipica della sismica a riflessione. I profili OBS analizzati sono stati acquisiti nell'area dell'Arco Ellenico e, i risultati ottenuti, hanno permesso di riconoscere le strutture geologiche principali e i meccanismi dell’evoluzione tettonica. L'utilizzo del WED ha migliorato la risoluzione delle sezioni finali rispetto a quanto ottenibile con le correzioni statiche classiche. Per confronto è stata applicata la metodologia WED anche a dati simici ad alta risoluzione a terra, risolvendo problemi di correzioni statiche e di strutturazioni tettoniche apparenti nell'area della Bassa Pianura Friulana.XXII Ciclo197

Chlorido(η 4-cyclo­octa-1,5-diene)(N,N′-diethyl­thio­urea-κS)rhodium(I)

In the title rhodium(I) complex, [RhCl(C8H12)(C5H12N2S)], N,N′-diethyl­thio­urea acts as a monodenate S-donor ligand. The rhodium(I) coordination sphere is completed by the Cl atom and the COD [= 1,5-cyclo­octa­diene] ligand inter­acting through the π-electrons of the double bonds. If the midpoints of these two bonds are taken into account, the Rh atom exhibits a distorted square-planar coordination. The syn conformation of the N,N′-diethyl­thio­urea ligand with respect to the Cl atom is stabilized by an intra­molecular N—H⋯Cl hydrogen bond. A weak inter­molecular N—H⋯Cl inter­action links mol­ecules along the a axis

CT and MR Imaging of Retroperitoneal Sarcomas: A Practical Guide for the Radiologist

Primary retroperitoneal sarcomas (RPS) represent around 10–16% of all sarcomas, with liposarcomas and leiomyosarcomas being the most common subtypes. RPS have some peculiar characteristics, imaging appearances, worse prognosis, and complications compared to other locations of sarcoma. Commonly, RPS primarily present as large masses, progressively encasing adjacent structures, causing mass effect, and complications. RPS diagnosis is often challenging, and these tumors may be overlooked; however, failure to recognize RPS characteristics leads to a worse prognosis for the patients. Surgery is the only recognized curative treatment, but the anatomical constraints of the retroperitoneum limit the ability to achieve wide resection margins; therefore, these tumors have a high rate of recurrence, and require long-term follow-up. The radiologist has an important role in the diagnosis of RPS, the definition of their extent, and their follow-up. Specific knowledge of the main imaging findings is required to reach an early diagnosis, and, ultimately, to guarantee the best patient management. This article provides an overview of the current knowledge regarding cross-sectional imaging features of patients with retroperitoneal sarcomas, presenting tips and tricks to improve imaging diagnosis of RPS

Imaging appearance of treated hepatocellular carcinoma.

Surgical resection and imaging guided treatments play a crucial role in the management of hepatocellular carcinoma (HCC). Although the primary end point of treatment of HCC is survival, radiological response could be a surrogate end point of survival, and has a key role in HCC decision-making process. However, radiological assessment of HCC treatment efficacy is often controversial. There are few doubts on the evaluation of surgical resection; in fact, all known tumor sites should be removed. However, an unenhancing partial linear peripheral halo, in most cases, surrounding a fluid collection reducing in size during follow-up is demonstrated in successfully resected tumor with bipolar radiofrequency electrosurgical device. Efficacy assessment of locoregional therapies is more controversial and differs between percutaneous ablation (e.g., radiofrequency ablation and percutaneous ethanol injection) and transarterial treatments (e.g., conventional transarterial chemoembolization, transarterial chemoembolization with drug eluting beads and radioembolization). Finally, a different approach should be used for new systemic agent that, though not reducing tumor mass, could have a benefit on survival by delaying tumor progression and death. The purpose of this brief article is to review HCC imaging appearance after treatment

Focal confluent fibrosis in cirrhotic liver: natural history studied with serial CT.

OBJECTIVE: The objective of this study was to assess the long-term natural history of focal confluent fibrosis in cirrhotic liver with CT. MATERIALS AND METHODS: Two radiologists retrospectively reviewed in consensus 118 liver CT examinations in 26 patients (19 men, seven women; age range, 32-68 years; mean age, 50 years) performed over approximately 6 years. Helical CT scans were obtained before and 30-35 and 65-70 seconds after injection of 125-150 mL of contrast medium at a rate of 4-5 mL/s. Proof of cirrhosis was based on liver transplantation (n = 6), biopsy (n = 9), or imaging findings (n = 11). The number, location, and attenuation of fibrotic lesions and presence of trapped vessels were evaluated. Variation of hepatic retraction associated with the development of focal confluent fibrosis lesions was assessed using the ellipsoid volume formula and an arbitrary retraction index. RESULTS: Each radiologist identified 41 focal confluent fibrosis lesions. All lesions were identified by both radiologists. Twelve patients (46%) had a single lesion, 13 (50%) had two lesions, and one (4%) had three lesions. Thirty-four (83%) of 41 lesions were located in segment IV, VII, or VIII. Thirty-two lesions (78%) were hypoattenuating on unenhanced images, 25 lesions (61%) were hypoattenuating on hepatic arterial phase images, and 20 lesions (49%) were isoattenuating on portal venous phase images. Seven lesions (17%) were or became hyperattenuating at follow-up on portal venous phase images. Trapped vessels were found in six lesions (15%). The retraction index showed a significant increase over time (r = 0.423, p < or = 0.0001). CONCLUSION: The degree of capsule retraction associated with focal confluent fibrosis evolves with time and relates to the natural evolution of cirrhosis

Utility of CT in the diagnosis of pancreatic fistula after pancreaticoduodenectomy in patients with soft pancreas.

OBJECTIVE: The purpose of this study was to evaluate the sensitivity and specificity of routine performance of CT on postoperative day 7 in patients at high risk of pancreatic fistula after pancreaticoduodenectomy. MATERIALS AND METHODS: Two radiologists analyzed images from CT examinations of 50 patients with soft pancreas 7 days after pancreaticoduodenectomy. Pancreatic fistula was defined at CT as a fluid collection close to the pancreaticogastric or pancreaticojejunal anastomosis. Clinicobiologic criteria for the diagnosis of pancreatic fistula were drain output of any measurable volume of fluid on or after postoperative day 3 that had an amylase content more than three times the serum amylase activity. The final diagnosis of pancreatic fistula was rendered on the basis of clinicobiologic data at hospital discharge or at first readmission. RESULTS: At hospital discharge or at first readmission, 27 of 50 patients (54%) had a pancreatic fistula. On postoperative day 7, 30 patients (60%) had a total of 51 fluid collections, and CT showed a fluid collection close to the pancreaticogastric or pancreaticojejunal anastomosis in 21 of 51 cases. CT had a sensitivity of 63% (17/27 patients) and a specificity of 83% (19/23 patients) for the diagnosis of pancreatic fistula with four false-positive and 10 false-negative findings. The diagnosis of pancreatic fistula on the basis of clinicobiologic criteria on postoperative day 7 was made in 22 of 27 patients (81%), whereas five cases were false-negative. Four of these patients had CT evidence of pancreatic fistula. CONCLUSION: In patients at high risk who have undergone pancreaticoduodenectomy, systematic postoperative CT may be proposed as a complementary tool in the diagnosis of pancreatic fistula, particularly for detection of clinically occult pancreatic fistula

Focal nodular hyperplasia: a weight-based, intraindividual comparison of gadobenate dimeglumine and gadoxetate disodium-enhanced MRI

PURPOSE: We aimed to qualitatively and quantitatively compare the enhancement pattern of focal nodular hyperplasia after gadobenate dimeglumine and gadoxetate disodium injection in the same patient. METHODS: 1.5 T magnetic resonance imaging (MRI) examinations of 16 patients with 21 focal nodular hyperplasias studied after the injection of both contrast media were evaluated. Both MRI studies were performed in all patients. A qualitative analysis was performed evaluating each lesion in all phases. For quantitative analysis we calculated signal intensity ratio, lesion-to-liver contrast ratio and liver parenchyma signal intensity gain on hepatobiliary phase. Statistical analysis was performed with the Wilcoxon sign-rank test for clustered paired data and the McNemar test for paired frequencies. A P value < 0.05 was considered statistically significant. RESULTS: At qualitative analysis no statistically significant differences were evident during any of the contrast-enhanced phases. Signal intensity ratio (P = 0.048), lesion-to-liver contrast ratio (P = 0.032) and liver parenchyma signal intensity gain (P = 0.012) were significantly higher on hepatobiliary phase after gadoxetate disodium injection. CONCLUSION: There were no significant differences in the MRI findings of focal nodular hyperplasia after the injection of a weight-based dose of either gadobenate dimeglumine or gadoxetate disodium

Advances in liver US, CT, and MRI: moving toward the future

Over the past two decades, the epidemiology of chronic liver disease has changed with an increase in the prevalence of nonalcoholic fatty liver disease in parallel to the advent of curative treatments for hepatitis C. Recent developments provided new tools for diagnosis and monitoring of liver diseases based on ultrasound (US), computed tomography (CT), and magnetic resonance imaging (MRI), as applied for assessing steatosis, fibrosis, and focal lesions. This narrative review aims to discuss the emerging approaches for qualitative and quantitative liver imaging, focusing on those expected to become adopted in clinical practice in the next 5 to 10 years. While radiomics is an emerging tool for many of these applications, dedicated techniques have been investigated for US (controlled attenuation parameter, backscatter coefficient, elastography methods such as point shear wave elastography [pSWE] and transient elastography [TE], novel Doppler techniques, and three-dimensional contrast-enhanced ultrasound [3D-CEUS]), CT (dual-energy, spectral photon counting, extracellular volume fraction, perfusion, and surface nodularity), and MRI (proton density fat fraction [PDFF], elastography [MRE], contrast enhancement index, relative enhancement, T1 mapping on the hepatobiliary phase, perfusion). Concurrently, the advent of abbreviated MRI protocols will help fulfill an increasing number of examination requests in an era of healthcare resource constraints

Whipple's pancreaticoduodenectomy: Surgical technique and perioperative clinical outcomes in a single center

Introduction: Pancreatic cancer is the fourth cause of death from cancer in Western countries. The radical surgical resection is the only curative option for this pathology. The prevalence of this disease increases with age in population. The causes of pancreatic cancer are unknown, but we consider risk factors like smoke and tobacco usage, alcohol consumption coffee, history of diabetes or chronic pancreatitis. In this study we report our experience in the treatment of resectable pancreatic cancer and periampullary neoplasms with particular attention to evaluate the evolution of surgical technique and the clinical postoperative outcomes. Methods: In our Department between January 2010 and December 2014 we performed a total of 97 pancreaticoduodenectomy. We considered only resectable pancreatic cancer and periampullary neoplasms defined by absence of distant metastases, absence of local tumor extension to the celiac axis and hepatic artery as the lack of involvement of the superior mesenteric vasculature. None of these patients received neoadjuvant chemotherapy. Results: The mean age of these patients was 64.5 years. Jaundice was the commonest presenting symptom associated to anorexia and weight loss. The mean operative time was 295min (±55min). The mean blood loss was 450ml and median blood transfusion was 1 units. 12.1% of patients had an intra-abdominal complication. The commonest complication was Delayed Gastric Emptying responsable of increased length of hospital stay and readmission rate. Postoperative pancreatic fistula of grade C occurred in 4 patients. 2 patients developed a postpancreatectomy hemorrhage. Perioperative mortality was 4.1%. Conclusion: Pancreaticoduodenectomy is a complex surgical technique and the associated high morbidity and mortality resulted in initial reluctance to adopt this surgery for the management of pancreatic and periampullary tumors. Surgical outcomes of pancreatic surgery are better at high-volume experienced center reporting mortality rates below 5%. We perform an end-to-side duct-to-mucosa pancreaticojejunostomy with routinely use of internal pancreatic stent. However no one technique has been shown to definitely be the solution to the problem of postoperative pancreatic fistula. At our center we have a reasonable volume and our data are comparable to literature data