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MRI has emerged as the most comprehensive non-invasive diagnostic tool for liver diseases. In recent years, the value of MRI in hepatology has been significantly enhanced by a wide range of contrast agents, both clinically available and under development, that add functional information to anatomically detailed morphological images, or increase the distinction between normal and pathological tissues by targeting molecular and cellular events. Several classes of contrast agents are available for contrast-enhanced hepatic MRI, including i) conventional non-specific extracellular fluid contrast agents for assessing tissue perfusion; ii) hepatobiliary-specific contrast agents that are taken up by functioning hepatocytes and excreted through the biliary system for evaluating hepatobiliary function; iii) superparamagnetic iron oxide particles that accumulate in Kupffer cells; and iv) novel molecular contrast agents that are biochemically targeted to specific molecular/cellular processes for staging liver diseases or detecting treatment responses. The use of different functional and molecular MRI methods enables the non-invasive assessment of disease burden, progression, and treatment response in a variety of liver diseases. A high diagnostic performance can be achieved with MRI by combining imaging biomarkers. [ABSTRACT FROM AUTHOR]

To implement a new daily peer learning (PL) conference which incorporates faculty and trainees within the abdominal imaging division of a large academic medical center, and to determine participants' level of satisfaction and preference over the pre-existing peer review (PR) model. We replaced our pre-existing PR-based tool with a daily hour-long case-based PL teaching conference over a 3-month pilot period. Faculty and trainees were surveyed about their experience at the end of the pilot period. A total of 711 cases were logged during the pilot period (median 9 cases per day). We received 30 survey responses from a total of 48 eligible participants. Survey responses from both faculty and trainees on the new PL conference were overwhelmingly favorable, including unanimous support for permanently replacing the existing PR tool with the new PL conference. Our successful pilot of a daily PL conference replacing an existing PR tool adds to the growing body of evidence of radiologists strongly supporting PL based processes over PR. Our paradigm of actively involving trainees within the process can serve as a model for other institutions. • Peer learning is rapidly increasing in popularity as an alternative to traditional peer review. • Surveyed radiologists unanimously preferred participating in peer learning rather than peer review. • Trainees enjoyed participating in peer learning conferences and found the experience to be educational. [ABSTRACT FROM AUTHOR]

Background: Dynamic survival data based on time already survived are lacking for resected borderline resectable/locally advanced (BR/LA) pancreatic ductal adenocarcinoma (PDAC) patients who received total neoadjuvant therapy (TNT) with FOLFIRINOX followed by chemoradiation. Conditional survival, i.e., the probability of surviving an additional length of time after having already survived an amount of time, offers such information. We aimed to determine actuarial and conditional overall (OS, COS) and disease-free survival (DFS, CDFS) among this cohort. Methods: Clinicopathologic data were retrospectively collected for resected BR/LA PDAC patients who received TNT (2011–2019). COS and CDFS rates were calculated for patients being event (death/recurrence)-free at multiple intervals and by recurrence status. Results: After a median follow-up of 32.1 months, the 183 patients had a median OS and DFS of 39.1 months and 16.8 months, respectively. COS and CDFS increased as a function of time already survived. The probability of surviving an additional 24 months if a patient survived 2 years post-operatively was 70%, whereas the 4-year actuarial OS was 47%. Similarly, the probability of surviving disease-free an additional 24 months after 2 years was 66%, while actuarial 48-month DFS was 27%. COS for disease-free patients increased further over time. For patients remaining disease-free 12 months post-operatively, BR vs. LA status at diagnosis, tumor ≤ 4 cm at diagnosis, and R0 resection were independent predictors of favorable additional OS and DFS. Conclusions: For resected TNT-treated BR/LA PDAC patients, the probability of surviving an additional length of time increases as a function of survival already accrued. Dynamic survival estimates may allow personalized follow-up and counseling. [ABSTRACT FROM AUTHOR]

The purpose of this study was to determine if CT and MRI features can accurately differentiate mucinous cystic neoplasms (MCNs) from simple liver cysts and to compare accuracy of CT and MRI in detecting these features. Eighty-four surgically treated lesions with pre-operative CT or MRI were evaluated by two abdominal radiologists for upstream biliary dilatation, perfusional change, internal hemorrhage, thin septations, thick septations/nodularity, lobar location, and number of coexistent liver cysts. Odds ratios, sensitivities, specificities, and positive and negative predictive values were calculated for association of each feature with MCNs. Of 84 liver lesions, 13 (15%) were MCNs, all in women, and 71 (85%) were simple cysts, in 59 women and 12 men. Thick septations/nodularity, upstream biliary dilation, thin septations, internal hemorrhage, perfusional change, and fewer than 3 coexistent liver cysts were more frequent in MCNs than in simple cysts. The combination of thick septations/nodularity and at least one additional associated feature showed high specificity for MCNs (94–98%). MRI detected significant associations of biliary dilation, thin septations, and hemorrhage/debris with MCNs which CT did not. Surgically treated MCNs of the liver with preoperative imaging occurred at our institution only in women. Thick septations or nodularity, biliary dilation, thin septations, internal hemorrhage or debris, perfusional change, and fewer than 3 coexistent liver cysts are features that help differentiate MCNs from simple cysts. MRI has advantages over CT in detecting these features. • Mucinous cystic neoplasms of the liver and bile ducts are rare. • Imaging can differentiate mucinous cystic neoplasms from simple liver cysts. • MRI has advantages over CT in detecting differentiating features. [ABSTRACT FROM AUTHOR]

Background: The survival benefit of negative margins for hepatocellular carcinoma (HCC) has been demonstrated. However, there is no consensus regarding the optimal resection margin width. We assessed the impact of hepatic resection margin width for solitary HCC on overall (OS), recurrence-free (RFS), and liver-specific recurrence-free survival (LSRFS). Methods: Clinicopathologic data were retrospectively collected for solitary HCC patients who underwent a negative margin hepatectomy (1992–2015). Margin width was categorized in tertiles as "narrow" (≤ 0.3 cm), "intermediate" (0.31–1.0 cm), or "wide" (> 1.0 cm). Survival was compared among groups. Results: Of the 178 included patients, most were male (76%); median age, MELD score, and tumor size were 63 years, 8, and 5.2 cm, respectively; 93% were Child-Pugh class A. Median margin width was 0.5 cm. Median follow-up and OS were 47.8 months and 76.7 months, respectively. There was no significant survival difference among narrow, intermediate, and wide margin groups with a median OS of 53 months (IQR 21–not reached [NR]), 74 months (IQR 14–138), and 97 months (IQR 37–142) (p = 0.87), respectively. Median RFS was 33.0 months; again, there was no difference among narrow, intermediate, and wide margin groups with a median of 31 months (IQR 18–NR), 45 months (IQR 14–NR), and 27 months (IQR 11–NR), respectively (p = 0.66). Median LSRFS was 63.0 months (IQR 14–NR) with no difference among groups (p = 0.87). In multivariate analyses, margin width was not associated with OS (p = 0.77), RFS (p = 0.74), or LSRFS (p = 0.92). Findings were similar in all subgroups analyzed (≤ 5 cm, > 5 cm, microvascular invasion, T1, T2/T3, anatomical or non-anatomical resection, major or minor hepatectomy). Conclusions: Narrow margins appear to be oncologically safe and the feasibility of achieving wide margins should not determine resectability. [ABSTRACT FROM AUTHOR]

The aim of this study was to compare PET/MR enterography with ileocolonoscopy regarding patients' acceptance and their future preference. Between October 2014 and February 2018 one-hundred-eleven patients underwent PET/MR enterography and ileocolonoscopy within 2 weeks. Overall acceptance of each modality was rated using a 10-point Likert scale with higher score indicating worse experience. Wilcoxon test was used to assess difference. Patients' acceptance of bowel cleansing and oral intake of contrast agent was analyzed in the same way. Furthermore, to find out if diagnosis, gender and age might influence patients' acceptance and future preference, Mann-Whitney U test for ordinal and Chi-squared test for categorical parameters were applied. 77 patients (47 females) with a mean age of 44.5 years and diagnosed ulcerative colitis (UC; n = 46) and Crohn's disease (CD; n = 31), were included in the analysis. Overall, ileocolonoscopy was significantly better rated than PET/MR enterography (p < 0.001). Bowel cleansing was worse tolerated than oral intake of liquid (p < 0.001). Patients with CD preferred PET/MR enterography as future screening method, while UC patients favored ileocolonoscopy (p = 0.012). PET/MR enterography tended to be better accepted by CD patients (p = 0.08). Females tolerated both bowel cleansing and oral contrast agent worse than males (p = 0.05 and 0.047). No significant difference between different age groups was found. Ileocolonoscopy was rated as better tolerable than PET/MR and the overall rate for future preference was very similar. Optimization of both modalities might enhance patients' acceptance. • Ileocolonoscopy was rated as better tolerable than PET/MR enterography in patients with inflammatory disease. • Patients with CD favored PET/MR enterography, whereas patients with UC preferred ileocolonoscopy as future screening method. • Females tolerated both ileocolonoscopy and PET/MR enterography worse than males. [ABSTRACT FROM AUTHOR]

• Hybrid PET/MR imaging may be superior to conventional MR or PET/CT imaging in visualizing disease activity in inflammatory bowel diseases. • Standardization of technical aspects of imaging is of paramount importance in ensuring the reproducibility of imaging outputs. • PET/MR imaging could contribute to follow up of patients with IBD, with determining probability of response to treatment and providing prognostication about long term clinical outcome. Positron emission tomography (PET) magnetic resonance (MR) enterography is a novel hybrid imaging technique that is gaining popularity in the study of complex inflammatory disorders of the gastrointestinal system, such as inflammatory bowel disease (IBD). This imaging technique combines the metabolic information of PET imaging with the spatial resolution and soft tissue contrast of MR imaging. Several studies have suggested potential roles for PET/MR imaging in determining the activity status of IBD, evaluating treatment response, stratifying risk, and predicting long-term clinical outcomes. However, there are challenges in generalizing findings due to limited studies, technical aspects of hybrid MR/PET imaging, and clinical indications of this imaging modality. This review aims to further elucidate the possible role of PET/MR in IBD, highlight important technical aspects of imaging, and address potential pitfalls and prospects of this modality in IBDs. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: To compare the performance of PET/MRI imaging using MR attenuation correction (MRAC) (DIXON-based 4-segment -map) in breast cancer patients with that of PET/CT using CT-based attenuation correction and to compare the quantification accuracy in lesions and in normal organ tissues. Methods: A total of 36 patients underwent a whole-body PET/CT scan 1h after injection and an average of 62min later a second scan using a hybrid PET/MRI system. PET/MRI and PET/CT were compared visually by rating anatomic allocation and image contrast. Regional tracer uptake in lesions was quantified using volumes of interest, and maximal and mean standardized uptake values (SUVmax and SUVmean, respectively) were calculated. Metabolic tumor volume (MTV) of each lesion was computed on PET/MRI and PET/CT. Tracer uptake in normal organ tissue was assessed as SUVmax and SUVmean in liver, spleen, left ventricular myocardium, lung, and muscle. Results: Overall 74 FDG positive lesions were visualized by both PET/CT and PET/MRI. No significant differences in anatomic allocation scores were found between PET/CT and PERT/MRI, while contrast score of lesions on PET/MRI was significantly higher. Both SUVmax and SUVmean of lesions were significantly higher on PET/MRI than on PET/CT, with strong correlations between PET/MRI and PET/CT data (ρ =0.71–0.88). MTVs of all lesions were 4% lower on PET/MRI than on PET/CT, but no statistically significant difference was observed, and an excellent correlation between measurements of MTV with PET/MRI and PET/CT was found (ρ =0.95–0.97; p <0.0001). Both SUVmax and SUVmean were significantly lower by PET/MRI than by PET/CT for lung, liver and muscle, no significant difference was observed for spleen, while either SUVmax and SUVmean of myocardium were significantly higher by PET/MRI. High correlations were found between PET/MRI and PET/CT for both SUVmax and SUVmean of the left ventricular myocardium (ρ =0.91; p <0.0001), while moderate correlations were found for the other normal organ tissues (ρ =0.36–0.61; p <0.05). Conclusions: PET/MRI showed equivalent performance in terms of qualitative lesion detection to PET/CT. Despite significant differences in tracer uptake quantification, due to either methodological and biological factors, PET/MRI and PET/CT measurements in lesions and normal organ tissues correlated well. This study demonstrates that integrated whole-body PET/MRI is feasible in a clinical setting with high quality and in a short examination time. [Copyright &y& Elsevier]