Serotonin immunoreactive pancreatic neuroendocrine neoplasm associated with main pancreatic duct dilation: a recognizable entity with excellent long-term outcome.

OBJECTIVES: Dilatation of the main pancreatic duct (MPD) is rare in pancreatic neuroendocrine neoplasm (panNEN) and may be due to different mechanisms. We compared the imaging and pathological characteristics as well as the outcome after resection of positive (S+) and negative (S-) serotonin immunoreactive panNENs causing MPD dilatation. METHODS: This retrospective study included patients with panNEN, with MPD dilatation (≥ 4 mm) on preoperative CT/MRI and resected between 2005 and 2019. Clinical, radiological, and pathological features were compared between S+ and S- panNENs. Imaging features associated with S+ panNEN were identified using logistic regression analysis. The diagnostic performance of imaging for the differentiation of S+ and S- panNENs was assessed by ROC curve analysis. Recurrence-free survival (RFS) was compared between the two groups. RESULTS: The final population of 60 panNENs included 20/60 (33%) S+ panNENs. S+ panNENs were smaller (median 12.5 mm vs. 33 mm; p < 0.01), more frequently hyperattenuating/intense on portal venous phase at CT/MRI (95% vs. 25%, p < 0.01), and presented with more fibrotic stroma on pathology (60.7 ± 16% vs. 40.7 ± 12.8%; p < 0.01) than S- panNENs. Tumor size was the only imaging factor associated with S+ panNEN on multivariate analysis. A tumor size ≤ 20 mm had 95% sensitivity and 90% specificity for the diagnosis of S+ panNEN. Among 52 patients without synchronous liver metastases, recurrence occurred in 1/20 (5%) with S+ panNEN and 18/32 (56%) with S- panNEN (p < 0.01). Median RFS was not reached in S+ panNENs and was 31.3 months in S- panNENs (p < 0.01). CONCLUSIONS: In panNENs with MPD dilatation, serotonin positivity is associated with smaller size, extensive fibrotic stroma, and better long-term outcomes. KEY POINTS: • S+ panNENs showed a higher percentage of fibrotic stroma, higher microvessel density, and lower proliferation index (Ki-67) compared to S- panNENs. • Radiologically, S+ panNENs causing dilatation of the MPD were characterized by a small size (< = 20 mm) and a persistent enhancement on portal phase on both CT and MRI. • Patients with S+ panNENs presented with longer RFS when compared to those with S- panNENs.

Ultrasonic Adaptive Sound Speed Estimation for the Diagnosis and Quantification of Hepatic Steatosis: A Pilot Study.

PURPOSE: To evaluate the ability of a new ultrasound (US) method based on sound speed estimation (SSE) with respect to the detection, quantification, and grading of hepatic steatosis using magnetic resonance (MR) proton density fat fraction (PDFF) as the reference standard and to calculate one US fat index based on the patient's SSE. MATERIALS AND METHODS: This study received local IRB approval. Written informed consent was obtained from patients. We consecutively included N = 50 patients as the training cohort and a further N = 50 as the validation cohort who underwent both SSE and abdominal MR. Hepatic steatosis was classified according to MR-PDFF cutoffs as: S0 ≤ 6.5 %, S1 6.5 to 16.5 %, S2 16.5 to 22 %, S3 ≥ 22 %. Receiver operating curve analysis was performed to evaluate the diagnostic performance of SSE in the diagnosis of steatosis (S1-S3). Based on the optimal data fit derived from our study, we proposed a correspondence between the MR-PDFF and a US fat index. Coefficient of determination R2 was used to evaluate fit quality and was considered robust when R2 > 0.6. RESULTS: The training and validation cohorts presented mean SSE values of 1.570 ±â€Š0.026 and 1.568 ±â€Š0.023 mm/µs for S0 and 1.521 ±â€Š0.031 and 1.514 ±â€Š0.019 mm/µs for S1-S3 (p < 0.01) patients, respectively. An SSE threshold of ≤ 1.537 mm/µs had a sensitivity of 80 % and a specificity of 85.7 % in the diagnosis of steatosis (S1-S3) in the training cohort. Robust correspondence between MR-PDFF and the US fat index was found both for the training (R2 = 0.73) and the validation cohort (R2 = 0.76). CONCLUSION: SSE can be used to detect, quantify and grade liver steatosis and to calculate a US fat index.

Ultrasonic fat fraction quantification using in vivo adaptive sound speed estimation.

The non-invasive quantification of human tissue fat fraction using easily scalable and accessible imaging technologies is crucial for the diagnosis of many diseases including liver steatosis. Here, we propose a non-invasive quantification of fat content using a highly accessible ultrasonic imaging technology. Ultrasonic echoes backscattered from human liver tissues are recombined to synthetize echoes of a virtual point-like reflector within the organs. This virtual point-like reflector is an ultrasonic analogue of artificial stars generated by laser beams in the field of astronomy, which are used to estimate the aberrations induced in the propagation medium. Here, the ultrasonic echoes from the point-like reflector provide an estimate of the Green's function relating the ultrasonic array and the reflector location and consequently represent a measurement of the aberrations induced along the ultrasonic beam travel path. Maximizing the spatial coherence of echoes backscattered from this targeted region provides an estimate of the acoustic sound speed while iteratively making the reflector more echogenic. The acoustic sound speed is dependent of the organ fat content, and we derive and cross-validate a theoretical equation relating acoustic sound speed and fat content both in phantom experiments and humans. An ultrasound-based fat fraction was found to be highly correlated with the oil paraffin concentration (R 2 = 0.985) in phantoms and well correlated with the gold standard magnetic resonance imaging proton density fat fraction measurements (R 2 = 0.73) in patients.

Robust sound speed estimation for ultrasound-based hepatic steatosis assessment.

Hepatic steatosis is a common condition, the prevalence of which is increasing along with non-alcoholic fatty liver disease (NAFLD). Currently, the most accurate noninvasive imaging method for diagnosing and quantifying hepatic steatosis is MRI, which estimates the proton-density fat fraction (PDFF) as a measure of fractional fat content. However, MRI suffers several limitations including cost, contra-indications and poor availability. Although conventional ultrasound is widely used by radiologists for hepatic steatosis assessment, it remains qualitative and operator dependent. Interestingly, the speed of sound within soft tissues is known to vary slightly from muscle (1.575 mm · µs-1) to fat (1.450 mm · µs-1). Building upon this fact, steatosis could affect liver sound speed when the fat content increases. The main objectives of this study are to propose a robust method for sound speed estimation (SSE) locally in the liver and to assess its accuracy for steatosis detection and staging. This technique was first validated on two phantoms and SSE was assessed with a precision of 0.006 and 0.003 mm · µs-1 respectively for the two phantoms. Then a preliminary clinical trial (N = 17 patients) was performed. SSE results was found to be highly correlated with MRI proton density fat fraction (R 2 = 0.69) and biopsy (AUROC = 0.952) results. This new method based on the assessment of spatio-temporal properties of the local speckle noise for SSE provides an efficient way to diagnose and stage hepatic steatosis.

Grading lung neuroendocrine tumors: Controversies in search of a solution.

BACKGROUND: Pathological grading of tumors is a way to measure biological aggressiveness. In lung neuroendocrine tumors (NET), grading is tautologically included into the current 2015 WHO histologic classification. Little is known, however, about alternative grading systems in lung NET. METHODS: Through an extensive search of the English literature on lung NET (updated to April 2016), the following key questions were addressed: a) current concepts of grading; b) clinicians' requests for grading; c) functional parameters for grading; d) Ki-67 labeling index (LI) for grading; e) towards an effective pathology grading system. RESULTS: There is some room for inconsistency in the histologic classification of lung NET, likely due to the varying attribution of defining criteria. Innovative diffusion-weighted imaging upon magnetic resonance or molecular analysis could help separate indolent from aggressive lung NET, thus integrating a grading approach other than histology. Troubles in the clinical handling of metastatic or individual tumors when relying on morphology alone support the development of a lung-specific grading system for the more accurate prediction of prognosis and planning therapy in individual patients. To integrate the 2015 WHO classification using innovative grading based on Ki-67 LI, mitotic count and necrosis, a new proposal is emerging where three categories of lung NET are identified, namely Lu-NET G1, Lu-NET G2 and Lu-NET G3, which would allow tumors with similar behavior and therapy to be better handled according to their own biological potential. CONCLUSION: This new formulation of lung NET grading could have clinical relevance for the individual handling of patients.

US-guided percutaneous treatment and physical therapy in rotator cuff calcific tendinopathy of the shoulder: outcome at 3 and 12 months.

OBJECTIVES: To monitor the results of ultrasound (US)-guided percutaneous treatment of calcific tendinopathy of the shoulder at 12 months (T12) after treatment (T0). To verify the possible relations between some pre- and post-procedural variables with the clinical outcome at T12. METHODS: Forty-seven patients (26 female and 21 male) were enrolled in the study. Patients' approval and written informed consent were obtained. Symptoms were assessed by Constant Shoulder Score (CSS) at T0 and T12. Thirty of these also underwent a CSS control at 3 months (T3). The treatment efficacy was statistically tested for relation with location and type of calcification, characteristics of the tendon and subdeltoid bursa, impingement, and rehabilitation treatments. RESULTS: There was a significant increase in the average CSS value between T0 and T12 (40.7 vs. 75.3). The variables analysed did not show a statistically significant effect on the outcome at T12. A link was noticed only between patients' increasing age and score improvement, particularly among female subjects. CONCLUSION: US-guided treatment of calcific tendonitis is a viable therapeutic option. No pre- or intra-procedural parameters emerged which might help in predicting the outcome, apart from patients' needs in everyday life. KEY POINTS: • US-guided tcreatment of shoulder calcific tendinopathy is an excellent therapeutic option • Long-term results seem greatly affected by patients' features and needs in everyday life • No proven pre- or intra-procedural parameters emerged that might predict the outcome.

MR and CEUS monitoring of patients with severe rheumatoid arthritis treated with biological agents: a preliminary study.

PURPOSE: This study was done to propose a study protocol for patients with rheumatoid arthritis (RA) treated with biological agents, by evaluating the contribution of contrast-enhanced magnetic resonance (CE-MR) imaging, a software programme that calculates the volume of synovitis on CE-MR images, and contrast-enhanced ultrasound (CEUS). MATERIALS AND METHODS: Sixteen patients with RA receiving treatment with biologics were analysed. The patients underwent clinical examination, CE-MR imaging and CEUS on the same day. Images were postprocessed with the software and evaluated independently by three physicians in terms of RAMRIS (Rheumatoid Arthritis Magnetic Resonance Imaging Score), SAMIS (Simplified Rheumatoid Arthritis Magnetic Resonance Imaging Score) and CEUS grade. The techniques were correlated statistically. RESULTS: The RAMRIS and SAMIS scores were found to correlate statistically. CE-MR imaging correlated with the clinical data (p < 0.05), whereas CEUS did not. The data provided by the software did not correlate statistically with the other techniques. The most painful joint was consistently found to be the joint with most synovitis. CONCLUSIONS: CE-MR imaging may be used prior to treatment and for long-term follow-up. CEUS might be useful in the short-term follow-up, as it seems to provide an indication of the presence or absence of disease, though not of its severity. The software is a very useful tool that can supplement, but not replace, the other techniques.

Imaging of soft-tissue tumors.

The objective of this review is to highlight the major imaging characteristics of the main soft-tissue sarcoma histotypes observed in the group "Sarcomi" of the Istituto Oncologico Veneto in the last 5 years. A literature review was performed using PubMed and textbooks. Radiological imaging can guide the diagnosis for the subset of lesions that have typical clinical and imaging features. Soft-tissue tumors are common in clinical practice and a systematic clinical and imaging approach may guide the diagnosis.