Search

The high postoperative recurrence rates in hepatocellular carcinoma (HCC) remain a major hurdle in its management. Appropriate staging and treatment selection may alleviate the extent of fatal recurrence. However, effective methods to preoperatively evaluate pathophysiologic and molecular characteristics of HCC are lacking. Imaging plays a central role in HCC diagnosis and stratification due to the non-invasive diagnostic criteria. Vast and crucial information is hidden within image data. Other than providing a morphological sketch for lesion diagnosis, imaging could provide new insights to describe the pathophysiological and genetic landscape of HCC. Radiomics aims to facilitate diagnosis and prognosis of HCC using artificial intelligence techniques to harness the immense information contained in medical images. Radiomics produces a set of archetypal and robust imaging features that are correlated to key pathological or molecular biomarkers to preoperatively risk-stratify HCC patients. Inferred with outcome data, comprehensive combination of radiomic, clinical and/or multi-omics data could also improve direct prediction of response to treatment and prognosis. The evolution of radiomics is changing our understanding of personalized precision medicine in HCC management. Herein, we review the key techniques and clinical applications in HCC radiomics and discuss current limitations and future opportunities to improve clinical decision making. [ABSTRACT FROM AUTHOR]

The combination of PET and MRI is one of the recent advances of hybrid imaging. Yet to date, the adoption rate of PET/MRI systems has been rather slow. This seems to be partially caused by the high costs of PET/MRI systems and the need to verify an incremental benefit over PET/CT or sequential PET/CT and MRI. In analogy to PET/CT, the MRI part of PET/MRI was primarily used for anatomical imaging. Though this can be advantageous, for example in diseases where the superior soft tissue contrast of MRI is highly appreciated, the sole use of MRI for anatomical orientation lessens the potential of PET/MRI. Consequently, more recent studies focused on its multiparametric potential and employed diffusion weighted sequences and other functional imaging sequences in PET/MRI. This integration puts the focus on a more wholesome approach to PET/MR imaging, in terms of releasing its full potential for local primary staging based on multiparametric imaging and an included one-stop shop approach for whole-body staging. This approach as well as the implementation of computational analysis, in terms of radiomics analysis, has been shown valuable in several oncological diseases, as will be discussed in this review article. [ABSTRACT FROM AUTHOR]

The authors present a novel technique to detect and characterize LAA thrombus in humans using combined positron emission tomography (PET)/cardiac magnetic resonance (CMR) of a fibrin-binding radiotracer, [64Cu]FBP8. The detection of thrombus in the left atrial appendage (LAA) is vital in the prevention of stroke and is currently performed using transesophageal echocardiography (TEE). The metabolism and pharmacokinetics of [64Cu]FBP8 were studied in 8 healthy volunteers. Patients with atrial fibrillation and recent TEEs of the LAA (positive n = 12, negative n = 12) were injected with [64Cu]FBP8 and imaged with PET/CMR, including mapping the longitudinal magnetic relaxation time (T 1) in the LAA. [64Cu]FBP8 was stable to metabolism and was rapidly eliminated. The maximum standardized uptake value (SUV Max) in the LAA was significantly higher in the TEE-positive than TEE-negative subjects (median of 4.0 [interquartile range (IQR): 3.0-6.0] vs 2.3 [IQR: 2.1-2.5]; P < 0.001), with an area under the receiver-operating characteristic curve of 0.97. An SUV Max threshold of 2.6 provided a sensitivity of 100% and specificity of 84%. The minimum T 1 (T 1Min) in the LAA was 970 ms (IQR: 780-1,080 ms) vs 1,380 ms (IQR: 1,120-1,620 ms) (TEE positive vs TEE negative; P < 0.05), with some overlap between the groups. Logistic regression using SUV Max and T 1Min allowed all TEE-positive and TEE-negative subjects to be classified with 100% accuracy. PET/CMR of [64Cu]FBP8 is able to detect acute as well as older platelet-poor thrombi with excellent accuracy. Furthermore, the integrated PET/CMR approach provides useful information on the biological properties of thrombus such as fibrin and methemoglobin content. (Imaging of LAA Thrombosis; NCT03830320) [Display omitted] [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]

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]

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]

In this review article, we focus on the most recent applications of nuclear medicine techniques (mainly 99mTc/111In white blood cells (WBC) scan, [18F]-FDG-PET/CT, [18F]-FDG-PET/MRI, and 99mTc-IL-2 scintigraphy) in the study of children affected by peripheral bone osteomyelitis, fungal infections, inflammatory bowel diseases, and type 1 diabetes, owing to recent important published evidences of their role in the management of these diseases. For osteomyelitis in children, both bone scintigraphy and [18F]-FDG-PET have a major advantage of assessing the whole body in one imaging session to confirm or exclude multifocal involvement, whereas WBC scan has a limited role. In children with fungal infections, [18F]-FDG-PET can help in defining the best location for biopsy and can help in evaluating the extent of the infection and organs involved (also sites that were not yet clinically apparent), although its main role is for therapy monitoring. In inflammatory bowel diseases, and Crohn disease in particular, WBC scan has been successfully used for many years, but it is now used only in case of doubtful magnetic resonance (MR) or when MR cannot be performed and endoscopy is inconclusive. By contrast, there is an accumulating evidence of the role of [18F]-FDG-PET in management of children with Crohn disease, and PET/MR could be a versatile and innovative hybrid imaging technique that combines the metabolic information of PET with the high soft tissue resolution of MR, particularly for distinguishing fibrotic from active strictures. Finally, there are several new radiopharmaceuticals that specifically target inflammatory cells involved in the pathogenesis of insulitis aiming at developing new specific immunotherapies and to select children candidates to these treatments for improving their quality of life. [ABSTRACT FROM AUTHOR]

Abstract: Background: Short bowel syndrome (SBS) is a severe malabsorption caused by bowel loss. Congenital intestinal anomalies (CIA) detectable by prenatal ultrasound as jejunoileal atresia, meconium peritonitis, complicated meconium ileus, and fetal volvulus can be responsible for SBS. Aims: This study aims to investigate either frequency of SBS or the morbidity in CIA population during the first admission. Material and methods: Records of CIA treated from 1997 to 2003 were reviewed. The prenatal ultrasound findings were correlated with SBS. Student''s t and χ 2 tests were performed to analyze epidemiological data, growth at discharge, sepsis, liver disease, catheter-related complications, motor developmental delay, and hospital stay in CIA with and without SBS. Results: Forty-four CIA: SBS developed in 43%, ranging from 83% in volvulus to 0% in complicated meconium ileus. Thirty-six prenatal diagnoses: a strong correlation with SBS was observed in isolated dilated bowel (58%). In SBS neonates, birth weight, gestational age, and growth at discharge were statistically lower, whereas sepsis, motor delay, and hospital stay were statistically higher. Conclusions: Many neonates with CIA detectable by prenatal ultrasound develop SBS. Short bowel syndrome presents a significant higher morbidity. The counseling should stress the frequent association between CIA and SBS as well as the significant morbidity in SBS. [Copyright &y& Elsevier]

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]

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]

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]

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]