Imaging of the Liver and Pancreas: The Added Value of MRI.

MR is a powerful diagnostic tool in the diagnosis and management of most hepatic and pancreatic diseases. Thanks to its multiple sequences, the use of dedicated contrast media and special techniques, it allows a multiparametric approach able to provide both morphological and functional information for many pathological conditions. The knowledge of correct technique is fundamental in order to obtain a correct diagnosis. In this paper, different MR sequences will be illustrated in the evaluation of liver and pancreatic diseases, especially those sequences which provide information not otherwise obtainable with other imaging techniques. Practical MR protocols with the most common indications of MR in the study of the liver and pancreas are provided.

Pancreatic cancer detection with a non-contrast MR protocol: is it reliable?

PURPOSE: The pancreatic cancer (PC) is the 4th leading cancer-related death, becoming the second one by 2030, with a 5 year survival rate of 8%. Considering its increased incidence in high-risk categories compared to the general population, we aimed to validate a non-contrast MR protocol, to detect PC in its earliest phase, which could be suitable as a screening tool in high-risk patients. MATERIALS AND METHODS: In this retrospective study, we selected 200 patients (> 40 years) from our radiological database, which performed upper abdominal MRI between 2012 and 2017. 100 were negative for pancreatic lesions and 100 positive for pancreatic lesion (< 30 mm). The latter group included: 40 PDAC (pancreatic adenocarcinoma), 42 BD-IPMN (Branch Duct- Intraductal Papillary Mucinous Neoplasm), 10 PNET(pancreatic neuroendocrine tumor), 4 SCN(serous cystic neoplasm), 3 IPS(intrapancreatic spleen), 1 MCN(mucinous cystic neoplasm). Three readers (R1, R2 and R3) with a high, medium and low experience, respectively, analysed, first, the non-contrast MR sequences (single-shot T2w breath-hold, GE T1w FS, DWI and 2D/3D MRCP), and then the standard MR protocol, independently, randomly and anonymously. Readers identified or excluded the presence of pancreatic lesion, in both reading sessions. These results were compared with the histopathological diagnosis, and then divided into 3 different classes of lesions: all lesions, pancreatic adenocarcinoma and solid lesion. Mcnemar's test was used to compare the results. The inter-observer agreement was determined according to the kappa statistic in both protocols, and then the inter-protocol agreement was calculated. RESULTS: The non-contrast MR protocol has reached statistical parameters values ranging between 83% in SE (sensitivity) by R3 and 99% in NPV (negative predictive value) by R1. The standard MR protocol has reported slight increasing statistical parameters compared to those of the proposed one. However, there are not significant statistical differences between the both protocols. The proposed non-contrast MR protocol has reported the highest NPVs in the PDAC group detection (R1: 99%, R2: 99%, R3: 98%). In all groups of lesions, the agreement between the two protocols was excellent for each Reader ranging from 96 to 98%. CONCLUSION: The proposed non-contrast MR protocol showed high PC detection values and a time execution ≤ 20 min. Therefore, it can be proposed as a screening tool in high-risk patients.

Cystic pancreatic lesions: MR imaging findings and management.

Cystic pancreatic lesions (CPLs) are frequently casual findings in radiological examinations performed for other reasons in patients with unrelated symptoms. As they require different management according to their histological nature, differential diagnosis is essential. Radiologist plays a key role in the diagnosis and management of these lesions as imaging is able to correctly characterize most of them and thus address to a correct management. The first step for a correct characterization is to look for a communication between the CPLs and the main pancreatic duct, and then, it is essential to evaluate the morphology of the lesions. Age, sex and a history of previous pancreatic pathologies are important information to be used in the differential diagnosis. As some CPLs with different pathologic backgrounds can show the same morphological findings, differential diagnosis can be difficult, and thus, the final diagnosis can require other techniques, such as endoscopic ultrasound, endoscopic ultrasound-fine needle aspiration and endoscopic ultrasound-through the needle biopsy, and multidisciplinary management is important for a correct management.

Italian consensus guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms.

This report contains clinically oriented guidelines for the diagnostic work-up and follow-up of cystic pancreatic neoplasms in patients fit for treatment. The statements were elaborated by working groups of experts by searching and analysing the literature, and then underwent a consensus process using a modified Delphi procedure. The statements report recommendations regarding the most appropriate use and timing of various imaging techniques and of endoscopic ultrasound, the role of circulating and intracystic markers and the pathologic evaluation for the diagnosis and follow-up of cystic pancreatic neoplasms.

Efficacy of computer-aided detection as a second reader for 6-9-mm lesions at CT colonography: multicenter prospective trial.

PURPOSE: To assess the effect of computer-aided detection (CAD) as a second reader on the sensitivity and specificity of computed tomographic (CT) colonography in detecting 6-9-mm colorectal cancer (CRC) lesions. MATERIALS AND METHODS: Individuals with clinical indications for colonoscopy--either for symptoms or as part of participating in a surveillance program or CRC screening--were prospectively enrolled at one of 10 academic centers between July 2007 and May 2009. Institutional review board approval was obtained at each clinical site, and all participants provided written informed consent. All participants underwent CT colonography and colonoscopy on the same day. Experienced readers interpreted the CT colonography images unassisted and then reviewed all colorectal lesion-like structures pinpointed by the CAD algorithm. Segmental unblinding of CT colonoscopy findings at colonoscopy was utilized. The sensitivity and specificity of unassisted and CAD-assisted reading in identifying individuals with 6-9-mm lesions were calculated and compared by means of pairwise analysis. RESULTS: A total of 618 participants (mean age, 57.9 years; 54.5% male) were included in the final analysis. Of these participants, 464 (75.1%) had no lesions 6 mm or larger, and 52 (8.4%) had 6-9-mm lesions. The sensitivity of CT colonography with unassisted reading and that with CAD-assisted reading in identifying individuals with 6-9-mm lesions was 65.4% (95% confidence interval [CI]: 50.9%, 78.0%) and 76.9% (95% CI: 63.2%, 87.5%; P = .016), respectively. No significant change in specificity was observed: The specificity of CT colonography with unassisted and that with CAD-assisted reading was 91.8% (95% CI: 88.9%, 94.1%) and 90.9% (95% CI: 88.0%, 93.4%; P = .063), respectively. Evaluation of CAD candidates required an additional 1.6 minutes (25th-75th percentile: 1.0 minute to 3.4 minutes). CONCLUSION: The addition of CAD to reading performed by experienced readers resulted in a significant benefit in the detection of 6-9-mm polyps at CT colonography in this cohort. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120376/-/DC1.

Diagnostic accuracy of computed tomographic colonography for the detection of advanced neoplasia in individuals at increased risk of colorectal cancer.

CONTEXT: Computed tomographic (CT) colonography has been recognized as an alternative for colorectal cancer (CRC) screening in average-risk individuals, but less information is available on its performance in individuals at increased risk of CRC. OBJECTIVE: To assess the accuracy of CT colonography in detecting advanced colorectal neoplasia in asymptomatic individuals at increased risk of CRC using unblinded colonoscopy as the reference standard. DESIGN, SETTING, AND PARTICIPANTS: This was a multicenter, cross-sectional study. Individuals at increased risk of CRC due to either family history of advanced neoplasia in first-degree relatives, personal history of colorectal adenomas, or positive results from fecal occult blood tests (FOBTs) were recruited in 11 Italian centers and 1 Belgian center between December 2004 and May 2007. Each participant underwent CT colonography followed by colonoscopy on the same day. MAIN OUTCOME MEASURES: Sensitivity and specificity of CT colonography in detecting individuals with advanced neoplasia (ie, advanced adenoma or CRC) 6 mm or larger. RESULTS: Of 1103 participants, 937 were included in the final analysis: 373 cases in the family-history group, 343 in the group with personal history of adenomas, and 221 in the FOBT-positive group. Overall, CT colonography identified 151 of 177 participants with advanced neoplasia 6 mm or larger (sensitivity, 85.3%; 95% confidence interval [CI], 79.0%-90.0%) and correctly classified results as negative for 667 of 760 participants without such lesions (specificity, 87.8%; 95% CI, 85.2%-90.0%). The positive and negative predictive values were 61.9% (95% CI, 55.4%-68.0%) and 96.3% (95% CI, 94.6%-97.5%), respectively; after group stratification, a significantly lower negative predictive value was found for the FOBT-positive group (84.9%; 95% CI, 76.2%-91.3%; P < .001). CONCLUSIONS: In a group of persons at increased risk for CRC, CT colonography compared with colonoscopy resulted in a negative predictive value of 96.3% overall. When limited to FOBT-positive persons, the negative predictive value was 84.9%.

O sintoma e os impasses análise / The symptom and the deadlocks of the psychoanalytic clinic

A fim de considerar os impasses com os quais se defronta a psicanálise, este artigo aborda o conceito de sintoma tal como figura em parte das elaborações de Freud e Lacan. O trabalho se detém sobretudo no conceito lacaniano de objeto a, uma vez que sua elaboração permite pensar as dificuldades colocadas pela persistência do sintoma face ao trabalho de análise(AU)

In order to consider the deadlocks faced by psychoanalysis, this article discusses the concept of symptom as it appears in some elaborations of Freud and Lacan. The work concentrates especially on Lacan's concept of object a, since its elaboration allows us to evaluate the difficulties found in the persistence of the symptom during the work of analysis(AU)

O sintoma e os impasses análise / The symptom and the deadlocks of the psychoanalytic clinic

A fim de considerar os impasses com os quais se defronta a psicanálise, este artigo aborda o conceito de sintoma tal como figura em parte das elaborações de Freud e Lacan. O trabalho se detém sobretudo no conceito lacaniano de objeto a, uma vez que sua elaboração permite pensar as dificuldades colocadas pela persistência do sintoma face ao trabalho de análise.

In order to consider the deadlocks faced by psychoanalysis, this article discusses the concept of symptom as it appears in some elaborations of Freud and Lacan. The work concentrates especially on Lacan's concept of object a, since its elaboration allows us to evaluate the difficulties found in the persistence of the symptom during the work of analysis.