Added value of MRI tractography of peri-prostatic nerve plexus to conventional T2-WI in detection of extra-capsular extension of prostatic cancer.

PURPOSE: To evaluate the role of DTI (with fibretracking) and T2-weighted imaging (T2-WI) used together for predicting extra-capsular extension in patients with localized prostate cancer. METHOD AND MATERIALS: Thirty-six patients with biopsy-proven diagnosis of prostatic neoplasia performed MRI and underwent radical prostatectomy. Histopathological analysis showed ECE in 15/36 and capsule sparing in 21/36. By means of T2-WI, ECE was evaluated in a qualitative manner, according to PI-RADS v.2 (two groups with low and high risk of ECE); sensitivity and specificity were calculated for both groups. We performed a quantitative analysis on two tractographic parameters, fractional anisotropy (FA) and apparent diffusion coefficient (ADC) and computed the ratio between the lesion quadrant and its contralateral (L/H ratio). We compared L/H ratios of patients with and without ECE; ROC analyses were performed to determinate ECE cut-off values of tractographic parameters. These cut-off values were used in association with T2-WI to reassess patients and to evaluate whether specificity and sensitivity of ECE detection change. RESULTS: T2-WI showed a sensitivity of 80% and a specificity of 71% in detection of ECE. Tractography displayed a significant difference in L/H ratio for FA and ADC between patients with and without ECE. The simultaneous use of T2-WI and tractography revealed high sensitivity (100%) on patients with low suspect of ECE (on T2-WI) and high specificity (83%) on patients with high suspect of ECE (on T2-WI). CONCLUSION: The morphologic component of T2-weighted imaging and functional aspect of DTI should be interpreted together to more successfully assess the presence of ECE.

Surgery after FOLFIRINOX treatment for locally advanced and borderline resectable pancreatic cancer: increase in tumour attenuation on CT correlates with R0 resection.

OBJECTIVES: To assess factors associated with radical resection (R0) of pancreatic ductal adenocarcinoma (PDAC) after induction treatment with FOLFIRINOX. METHODS: Patients with either locally advanced (LA) and borderline resectable (BR) PDAC undergoing surgical exploration after FOLFIRINOX were retrospectively enrolled. Two pancreatic radiologists reviewed the CT blinded to the final outcome and assessed chemotherapy response and resectability. Patients were then divided into R0 resected (group A) and not resected/R1 resected (group B), which were compared. RESULTS: Of 59 patients included, 19 were defined as unresectable (32%), 33 borderline resectable (56%) and 7 resectable (12%) during the blind radiological evaluation after FOLFIRINOX. Once in a surgical setting, 27% were non-resectable, whereas 73% received surgical resection with a 70% R0 rate. Consequent sensitivity and specificity were 86% and 29%. At imaging review, significant decreases in longest tumour dimension were observed in both groups: from 32 mm (95% CI 15-55) to 21 (10-44) in group A and from 34 (18-70) to 26 (7-60) in group B, p < 0.05. However, a significant increase in tumour attenuation in all phases was only observed for R0 resected, from 52 HU (26-75) to 65 (35-92) in arterial phase (p < 0.001) and from 62 (36-96) to 78 (40-120) in the venous (p = 0.001). CONCLUSION: After neoadjuvant FOLFIRINOX, CT predicted resectability with acceptable sensitivity but low specificity. The observation of increased tumour attenuation at CT scan after FOLFIRINOX treatment might represent a reliable predictor of R0 resection. KEY POINTS: • CT drives the assessment of PDAC resectability after FOLFIRINOX • CT predicts resectability with acceptable sensitivity but low specificity • Significant increase in tumour attenuation was only observed for R0 resected PDAC • Tumour attenuation after FOLFIRINOX represents a reliable predictor of R0 resection.

Prevent Pancreatic Fistula after Pancreatoduodenectomy: Possible Role of Ultrasound Elastography.

BACKGROUND: The purpose of the study is to evaluate the utility of acoustic radiation force impulse (ARFI) on pancreatic tissue as a preoperative predictor of postoperative pancreatic fistula (POPF). Studied patients underwent exclusively to pancreaticoduodenectomy (PD) surgery. METHODS: Shear wave velocity of pancreas was measured using ARFI in 71 patients scheduled for PD. An intraoperative pancreas palpation was made by surgeons. A postoperative clinical evaluation to detect occurrence of POPF was performed. Sensitivity, specificity, positive and negative predictive values together with the accuracy of the method were investigated. RESULTS: Incidence of fistula observed in 17 patients with soft pancreas was approximately 53% vs. 47% without fistula. Percentage of patients without fistula was higher (66%) among 24 patients with medium parenchymal texture values, and was even higher (69%) in 26 patients with hard pancreas. Comparing ARFI and intraoperative pancreatic palpation, low wave velocity values (≤1.40 m/s) match 60% with soft parenchyma assessed by palpation and high values (>2 m/s) match 59% with hard pancreas on palpation. CONCLUSIONS: This study shows that ARFI elastography may be clinically useful as a preoperative predictor of pancreatic fistula following PD.

Classification of first-episode psychosis in a large cohort of patients using support vector machine and multiple kernel learning techniques.

First episode psychosis (FEP) patients are of particular interest for neuroimaging investigations because of the absence of confounding effects due to medications and chronicity. Nonetheless, imaging data are prone to heterogeneity because for example of age, gender or parameter setting differences. With this work, we wanted to take into account possible nuisance effects of age and gender differences across dataset, not correcting the data as a pre-processing step, but including the effect of nuisance covariates in the classification phase. To this aim, we developed a method which, based on multiple kernel learning (MKL), exploits the effect of these confounding variables with a subject-depending kernel weighting procedure. We applied this method to a dataset of cortical thickness obtained from structural magnetic resonance images (MRI) of 127 FEP patients and 127 healthy controls, who underwent either a 3Tesla (T) or a 1.5T MRI acquisition. We obtained good accuracies, notably better than those obtained with standard SVM or MKL methods, up to more than 80% for frontal and temporal areas. To our best knowledge, this is the largest classification study in FEP population, showing that fronto-temporal cortical thickness can be used as a potential marker to classify patients with psychosis.

Dual-energy CT of the brain: Comparison between DECT angiography-derived virtual unenhanced images and true unenhanced images in the detection of intracranial haemorrhage.

OBJECTIVE: To evaluate the diagnostic performance of virtual non-contrast (VNC) images in detecting intracranial haemorrhages (ICHs). METHODS: Sixty-seven consecutive patients with and 67 without ICH who underwent unenhanced brain CT and DECT angiography were included. Two radiologists independently evaluated VNC and true non-contrast (TNC) images for ICH presence and type. Inter-observer agreement for VNC and TNC image evaluation was calculated. Sensitivity and specificity of VNC images for ICH detection were calculated using Fisher's exact test. VNC and TNC images were compared for ICH extent (qualitatively and quantitatively) and conspicuity assessment. RESULTS: On TNC images 116 different haemorrhages were detected in 67 patients. Inter-observer agreement ranged from 0.98-1.00 for TNC images and from 0.86-1.00 for VNC images. VNC sensitivity ranged from 0.90-1, according to the different ICH types, and specificity from 0.97-1. Qualitatively, ICH extent was underestimated on VNC images in 11.9% of cases. Haemorrhage volume did not show statistically significant differences between VNC and TNC images. Mean haemorrhage conspicuity was significantly lower on VNC images than on TNC images for both readers (p < 0.001). CONCLUSION: VNC images are accurate for ICH detection. Haemorrhages are less conspicuous on VNC images and their extent may be underestimated. KEY POINTS: • VNC images represent a reproducible tool for detecting ICH. • ICH can be identified on VNC images with high sensitivity and specificity. • Intracranial haemorrhages are less conspicuous on VNC images than on TNC images. • Intracranial haemorrhages extent may be underestimated on VNC images.

Solid non-functioning endocrine tumors of the pancreas: correlating computed tomography and pathology.

BACKGROUND: Since prognosis and treatment of pancreatic endocrine tumors (pNET) are based on tumor grade, contrast-enhanced multidetector computed tomography (MDCT) features of solid non-functioning pNETs were studied and correlated with pathology tumor grading. METHODS: MDCTs of diagnosed pNETs were reviewed retrospectively. Each tumor was analyzed for location, size, homogeneity, margins, arterial and venous phase enhancement, main pancreatic duct diameter, calcifications, vascular invasion, lymph-nodes enlargement, and liver metastases. RESULTS: Of 154 pNETs presenting between January 2000 and May 2016 with available histology from resected specimen or biopsy, there were 65 G1, 72 G2 and 17 G3 pNETs. Tumor diameter varied significantly between the three groups. Tumors >20 mm were more frequently malignant and non-homogeneous than smaller tumors. G1 tumors were more commonly hypervascular and G3 tumors more often non-hypervascular in the arterial phase. Arterial phase non-hyperdensity and tumor non-homogeneity had a higher rate of metastatic lesions. Vascular invasion correlated with presence of metastases and histological grade. G3 tumors were all >20 mm (p = 0.007), more often non-hypervascular in the arterial phase (p = 0.0025), and non-hyperdense in the venous phase (p = 0.009), and showed more often vascular invasion (p = 0.0198). CONCLUSION: CT correlated with tumor grade; differentiating low-grade and high-grade pNETs through routine CT imaging might improve patient management.

Secretin-enhanced MR Imaging of the Pancreas.

Secretin is a hormone that stimulates the exocrine pancreatic secretion of bicarbonate-rich fluid from the acinar cells of the pancreas that accumulates within the pancreatic ductal lumen. The exogenous administration of secretin improves the visualization of pancreatic ducts at magnetic resonance (MR) cholangiopancreatography (MRCP), because of an enlargement of the pancreatic duct system and an increase of the fluid content within the lumen of the pancreatic ducts, responsible of an increase of MR signal. In this review, the technique of secretin-enhanced MRCP, which has the aim to depict the whole pancreatic duct system, the biliary tree, the major and minor papillae, and the duodenum, will be described. Because of the anatomic contiguity between the pancreas and the gastrointestinal tract, the presence of fluid within the stomach may overlap with the pancreatic duct system and therefore the pancreatic duct may be difficult to visualize, representing a potential source of diagnostic pitfalls. The technique to reduce the signal intensity of the static fluid present within the stomach and in the duodenal lumen is also described. The technique of secretin administration will be illustrated, with emphasis on the synchronization of secretin administration and MR image acquisition. Furthermore, the frequency and number of MRCP images necessary to achieve a temporal resolution adequate to visualize the physiologic changes in the pancreatic gland, induced by the administration of secretin, is described. The assessment of pancreatic, morphologic, and functional response to the administration of secretin, as depicted on MRCP images, will be illustrated. Finally, the indications for secretin-enhanced MRCP will be discussed to define which patients will benefit from secretin-enhanced MR imaging for their treatment planning. (©) RSNA, 2016.

Acoustic radiation force impulse with shear wave speed quantification of pancreatic masses: A prospective study.

BACKGROUND: Acoustic Radiation Force Impulse (ARFI) is a new ultrasound technique that evaluates mechanical properties of tissues. To evaluate the use of ARFI with shear waves speed quantification for pancreatic masses characterization during the ultrasound examination. METHODS: 123 pancreatic lesions were prospectively evaluated. Median shear waves speeds were compared with Mann-Whitney U test. Two reading methods were applied for the characterization of adenocarcinoma: more than one measurement above the top shear waves speed (SWS) value. Two reading methods were applied to diagnose mucinous lesion: at least 2 (method 1) or 3 (method 2) numerical measurements. Sensitivity, specificity, positive and negative predictive values and accuracy of each reading method were calculated. Forty volunteers were included for normal ARFI values. RESULTS: In the adenocarcinoma group median SWS value was 2.74 m/s. In the volunteers group the median SWS value was 1.17 m/s. Significant difference between SWS median values of adenocarcinoma and normal pancreas was found (P < 0.05). For the diagnosis of pancreatic solid masses if more than one measurement is above the top SWS value of 4.00 m/s results in the study, the diagnosis of ductal adenocarcinoma is highly specific with specificity and PPV of 100%. Good sensitivity (73.3%) and specificity (83.3%) were obtained for the characterization of mucinous cystic lesions. CONCLUSIONS: Acoustic Radiation Force Impulse imaging could help in the non-invasive characterization of solid and cystic lesions of the pancreas during a conventional US examination.

Ultrasound-guided percutaneous fine-needle aspiration of solid pancreatic neoplasms: 10-year experience with more than 2,000 cases and a review of the literature.

OBJECTIVES: To evaluate the diagnostic accuracy and complication rate of percutaneous ultrasound-guided fine-needle aspiration (US-FNA) of solid pancreatic neoplasms through the analysis of 10-year experiences of two centres. METHODS: Clinical, radiological and pathologic data of 2,024 patients with solid pancreatic masses who underwent US-FNAs were retrospectively evaluated. Indications for aspiration were: unresectable lesions before neo-adjuvant therapy; doubtful imaging findings; and suspicion of uncommon neoplasms with prognostic or therapeutic implications such as metastases or lymphoma. US-FNAs were performed using aspiration needles with a cytopathologist present in centre 1. In centre 2, cytologic samples were collected with Chiba needles and separately evaluated by a cytopathologist. RESULTS: US-FNA had a diagnostic sample rate of 92.2 % (centre 1: 95.9 %; centre 2: 87.2 %). US-FNA repetition after non-diagnostic samples provided a diagnosis in 86.3 % of cases. Sensitivity, specificity, positive and negative predictive values, and accuracy were 98.7 %, 100 %, 100 %, 75.5 %, and 98.7 %, respectively. The complication rate was 0.8 %. CONCLUSIONS: Percutaneous US-FNA is a sensitive, accurate and safe method for the invasive diagnosis of solid pancreatic neoplasms. The use of aspiration needles and the on-site presence of a cytopathologist may lead to a high rate of diagnostic samples, thus reducing the need for US-FNA repetition. KEY POINTS: • Percutaneous ultrasound-guided fine-needle aspiration of pancreatic neoplasms is sensitive and accurate. • The short-term complication rate of percutaneous ultrasound-guided fine-needle aspiration is low. • Technical aspects may influence the rate of diagnostic samples.

Identification of novel mutations in hemochromatosis genes by targeted next generation sequencing in Italian patients with unexplained iron overload.

Hereditary hemochromatosis, one of the commonest genetic disorder in Caucasians, is mainly associated to homozygosity for the C282Y mutation in the HFE gene, which is highly prevalent (allele frequency up to near 10% in Northern Europe) and easily detectable through a widely available "first level" molecular test. However, in certain geographical regions like the Mediterranean area, up to 30% of patients with a HH phenotype has a negative or non-diagnostic (i.e. simple heterozygosity) test, because of a known heterogeneity involving at least four other genes (HAMP, HJV, TFR2, and SLC40A1). Mutations in such genes are generally rare/private, making the diagnosis of atypical HH essentially a matter of exclusion in clinical practice (from here the term of "non-HFE" HH), unless cumbersome traditional sequencing is applied. We developed a Next Generation Sequencing (NGS)-based test targeting the five HH genes, and applied it to patients with clinically relevant iron overload (IO) and a non-diagnostic first level genetic test. We identified several mutations, some of which were novel (i.e. HFE W163X, HAMP R59X, and TFR2 D555N) and allowed molecular reclassification of "non-HFE" HH clinical diagnosis, particularly in some highly selected IO patients without concurring acquired risk factors. This NGS-based "second level" genetic test may represent a useful tool for molecular diagnosis of HH in patients in whom HH phenotype remains unexplained after the search of common HFE mutations.

Mucinous cystic neoplasms and serous cystadenomas arising in the body-tail of the pancreas: MR imaging characterization.

PURPOSE: To identify magnetic resonance (MR)/MR cholangiopancreatography (MRCP) imaging signs helpful in the differential diagnosis between serous cystadenomas (SCAs) and mucinous cystic neoplasms (MCNs), arising from the body/tail of the pancreas. MATERIAL AND METHODS: This retrospective study had institutional review board approval and informed consent was waived. Fifty-three patients with non-communicating cystic pancreatic neoplasm of the body/tail, undergoing MR/MRCP, were included. Qualitative image analysis assessed the macroscopic pattern, number of cysts, presence of central scar, contrast enhancement of peripheral wall, and mural nodules. Quantitative analysis assessed the maximum diameter of the neoplasm, thickness of the peripheral wall, and calibre of the upstream main pancreatic duct. RESULTS: Histopathology results revealed that 27/53 (51 %) were SCAs, 26/53 (49 %) were MCNs. Microcystic pattern was observed in 88.2 % of SCAs and 11.8 % of MCNs; macrocystic pattern was observed in 90.5 % of MCNs and 9.5 % of SCAs (p < 0.0001). Central scar was detected in 29.6 % of SCAs and no MCNs (p = 0.003). Contrast enhancement of the peripheral wall was evident in 99.5 % of MCNs and 11.5 % of SCAs (p < 0.0001); mural nodules were depicted in 94.1 % of MCNs and 5.9 % of SCAs (p < 0.0001). Median maximum diameter was 54 mm for MCNs, 32 mm for SCAs (p = 0.001); median wall thickness was 4 mm for MCNs, 2 mm for SCAs (p < 0.0001). CONCLUSIONS: Macrocystic pattern, enhancement of a peripheral wall and mural nodules are suggestive of MCNs; whereas microcystic pattern, lack of peripheral wall and central scar are suggestive of SCAs. KEY POINTS: • MCNs have macrocystic patterns, contrast enhancement of the peripheral wall and mural nodules • Microcystic pattern and central scar are suggestive of SCA • Mural nodules detected in MCNs correlate with epithelial dysplasia • Chronic obstructive pancreatitis is equally depicted in patients with MCNs and SCAs.

Santorinicele: secretin-enhanced magnetic resonance cholangiopancreatography findings before and after minor papilla sphincterotomy.

OBJECTIVES: To evaluate secretin-enhanced MRCP (S-MRCP) findings of patients with pancreas divisum and Santorinicele, before and after minor papilla sphincterotomy. METHODS: S-MRCP examinations of 519 patients with suspected pancreatic disease were included. Size of the main pancreatic duct, presence and calibre of Santorinicele were evaluated. Duodenal filling was assessed on dynamic images. After sphincterotomy the same parameters and the clinical findings were re-evaluated. RESULTS: Pancreas divisum was depicted in 55/519 patients (11 %) by MRCP and an additional 26/519 by S-MRCP (total 81/519, 16 %). Santorinicele was detected in 7/81 patients (8.6 %) with pancreas divisum by MRCP and an additional 20/81 by S-MRCP (total 27/81, 33 %). Dorsal duct in patients with Santorinicele was significantly larger in the head compared with patients with only pancreas divisum (p < 0.01), in basal conditions (average 2.4 versus 1.9 mm) and after secretin administration (average 3.0 versus 2.4 mm). Duodenal filling was impaired in 11/27 patients (41 %) with Santorinicele. After sphincterotomy significant reduction in size of Santorinicele (-33 %) and dorsal duct (-17 %), increase of pancreatic juice and symptoms improvement were observed. CONCLUSION: Secretin administration increases the accuracy of MRCP in detecting Santorinicele and demonstrates the impaired duodenal filling. S-MRCP is useful to assess results of sphincterotomy. KEY POINTS: • Secretin-enhanced MRCP gives anatomical and functional information on pancreatic outflow dynamics. • Santorinicele is a cystic dilatation of the termination of the Santorini duct. • S-MRCP images are the most useful to recognize the presence of Santorinicele. • Minor papilla sphincterotomy during ERCP is indicated in patients with Santorinicele.

Pancreatic duct abnormalities in focal autoimmune pancreatitis: MR/MRCP imaging findings.

AIM: To evaluate the magnetic resonance (MR) imaging-MR cholangiopancreatographic (MRCP) findings of focal forms of autoimmune pancreatitis (AIP) to describe ductal involvement at diagnosis. METHODS: MR examinations of 123 patients affected by AIP were analysed. We included 26 patients who satisfied International Consensus Diagnostic Criteria and were suffering from focal AIP. Image analysis included: site of parenchymal enlargement, main pancreatic duct (MPD) diameter, MPD stenosis, stricture length, presence of upstream dilation within the stricture, signal intensity, and pancreatic enhancement. RESULTS: Signal intensity abnormalities were localized in the head in 10/26 (38.5%) and in the body-tail in 16/26 (61.5%) patients. MRCP showed a single MPD stenosis in 12/26 (46.1%) and multiple MPD stenosis in 14/26 (53.8%) patients, without a dilation of the upstream MPD (mean: 3.83 mm). Lesions showed hypointensity on T1-weighted images in all patients, and hyperintensity on T2-weighted images in 22/26 (84.6%) patients. The affected parenchyma was hypovascular during the arterial phase in 25/26 (96.2%) patients with contrast retention. CONCLUSIONS: MR-MRCP are effective techniques for the diagnosis of AIP showing the loss of the physiological lobulation and the typical contrastographic appearance. The presence of multiple, long stenoses without an upstream MPD dilation at MRCP suggests the diagnosis of AIP, and can be useful in differential diagnosis of pancreatic adenocarcinoma. KEY POINTS: • MRI represents the gold standard in the diagnosis of AIP. • MRCP is an increasingly useful technique in the diagnosis of focal AIP. • MRCP could be a problem-solving tool in the differential diagnosis of AIP.

Collateral non cardiac findings in clinical routine CT coronary angiography: results from a multi-center registry.

PURPOSE: The aim of the study was to evaluate the prevalence of collateral findings detected in computed tomography coronary angiography (CTCA) in a multi-center registry. MATERIALS AND METHODS: We performed a retrospective review of 4303 patients (2719 males, mean age 60.3 ± 10.2 years) undergoing 64-slice CTCA for suspected or known coronary artery disease (CAD) at various academic institutions between 01/2006 and 09/2010. Collateral findings were recorded and scored as: non-significant (no signs of relevant pathology, not necessary to be reported), significant (clear signs of pathology, mandatory to be reported), or major (remarkable pathology, mandatory to be reported and further investigated). RESULTS: We detected 6886 non-cardiac findings (1.6 non cardiac finding per patient). Considering all centers, only 865/4303 (20.1 %) patients were completely without any additional finding. Overall, 2095 (30.4 %) non-significant, 4486 (65.2 %) significant, and 305 (4.4 %) major findings were detected. Among major findings, primary lung cancer was reported in 21 cases. In every center, most prevalent significant findings were mediastinal lymph nodes >1 cm. In 256 patients, collateral findings were clinically more relevant than coexisting CAD and justified the symptoms of patients. CONCLUSIONS: The prevalence of significant and major collateral findings in CTCA is high. Radiologists should carefully evaluate the entire scan volume in each patient.

MRI features of solid pseudopapillary neoplasm of the pancreas.

PURPOSE: To evaluate the magnetic resonance imaging (MRI) findings of solid pseudopapillary neoplasm (SPN) of the pancreas. METHODS AND MATERIALS: From January 2006 to December 2013, 41 patients with SPN of the pancreas were retrospectively evaluated. Inclusion criteria were the execution of an MR examination and tumor resection with an histopathological evaluation at our Institute. Exclusion criteria were the execution of an MR examination at other centers (14/41) and the execution of CT or ultrasonography (10/41) at our Institute. The qualitative analysis evaluated: location (head/body-tail), shape (round/oval/lobulated), margins (regular/irregular), and signal intensity on T1- and T2-weighted images compared to the surrounding pancreas (hypo-, iso-, or hyperintense and homogeneous or heterogeneous), appearance of MPD and the secondary ducts, and the presence of metastases and/or vascular involvement. The quantitative analysis included: maximum size of the lesion, wall thickness, and maximum diameter of the main pancreatic duct (MPD). RESULTS: The population comprised 17 women (median age: 31 year) with a median tumor size of 50.6 mm, a median wall thickness of 2 mm and median diameter of the MPD of 1.8 mm. 9/17 were at the head; 8/17 on the body/tail: respectively, 8/17 round, 6/17 oval, and 3/17 lobulated. All showed regular margins. On T1-weighted images 8/17 appeared homogeneously hypointense, 7/17 heterogeneously hypointense, and 2/17 heterogeneously hyperintense. On T2-weighted images 1/17 appeared homogeneously hyperintense and 16/17 heterogeneously hyperintense. No secondary ducts dilatations were detected. During the follow-up, one patient presented disease recurrence 48 months after surgery. CONCLUSIONS: MR imaging features can be highly suggestive for the diagnosis of SPN.

Congenital fibrosarcoma of the bowel: sonographic description of a rare case of neonatal intestinal obstruction.

A case of localization in the bowel of congenital fibrosarcoma (a rare soft-tissue tumor usually occurring in the extremities) causing intestinal obstruction in a newborn girl is described. A focal thickening of the ileal wall with features mimicking intussusception was identified at sonography; the final diagnosis was achieved by means of molecular analysis after surgical removal of the mass.

Autoimmune pancreatitis: multidetector-row computed tomography (MDCT) and magnetic resonance (MR) findings in the Italian experience.

Multidetector-row computed tomography (MDCT) and magnetic resonance (MR) imaging are currently the most frequently performed imaging modalities for the study of pancreatic disease. In cases of suspected autoimmune pancreatitis (AIP), a dynamic quadriphasic (precontrast, contrast-enhanced pancreatic, venous and late phases) study is recommended in both techniques. In the diffuse form of autoimmune pancreatitis (DAIP), the pancreatic parenchyma shows diffuse enlargement and appears, during the MDCT and MR contrast-enhanced pancreatic phase, diffusely hypodense and hypointense, respectively, compared to the spleen because of lymphoplasmacytic infiltration and pancreatic fibrosis. During the venous phase of MDCT and MR imaging, the parenchyma appears hyperdense and hyperintense, respectively, in comparison to the pancreatic phase. In the delayed phase of both imaging modalities, it shows retention of contrast media. A "capsule-like rim" may be recognised as a peripancreatic MDCT hyperdense and MR hypointense halo in the T2-weighted images, compared to the parenchyma. DAIP must be differentiated from non-necrotizing acute pancreatitis (NNAP) and lymphoma since both diseases show diffuse enlargement of the pancreatic parenchyma. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT has an important role. In the focal form of autoimmune pancreatitis (FAIP), the parenchyma shows segmental enlargement involving the head, the body-tail or the tail, with the same contrast pattern as the diffuse form on both modalities. FAIP needs to be differentiated from pancreatic adenocarcinoma to avoid unnecessary surgical procedures, since both diseases have similar clinical and imaging presentation. The differential diagnosis is clinically difficult, and dynamic contrast-enhanced MDCT and MR imaging both have an important role. MR cholangiopancreatography helps in the differential diagnosis. Furthermore, MDCT and MR imaging can identify the extrapancreatic manifestations of AIP, most commonly biliary, renal and retroperitoneal. Finally, in all cases of uncertain diagnosis, MDCT and/or MR follow-up after short-term treatment (2-3 weeks) with high-dose steroids can identify a significant reduction in size of the pancreatic parenchyma and, in FAIP, normalisation of the calibre of the upstream main pancreatic duct.

Acoustic radiation force impulse (ARFI) in the evaluation of the renal parenchymal stiffness in paediatric patients with vesicoureteral reflux: preliminary results.

OBJECTIVES: To prospectively evaluate acoustic radiation force impulse (ARFI) imaging of the kidneys in children with and without chronic renal disease. METHODS: Twenty-eight children (age range 9-16 years) with primary or secondary vesicoureteral reflux (≥ grade III) underwent scintigraphy and ultrasound with ARFI. Kidneys were divided-according to scintigraphy-into "affected" and "contralateral"; the results were compared with 16 age-matched healthy subjects. An ARFI value, expressed as speed (m/s) of wave propagation through the tissue, was calculated for each kidney through the mean of the values obtained at the upper, middle and lower third. The Wilcoxon test was used; P values <0.05 were considered statistically significant. RESULTS: The mean ARFI values obtained in the "affected" kidneys (5.70 ± 1.71 m/s) were significantly higher than those measured in both "contralateral" (4.09 ± 0.97, P < 0.0001) and "healthy" kidneys (3.13 ± 0.09, P < 0.0001). The difference between values in the "contralateral" kidneys and "healthy" ones was significant (P < 0.0001). The "affected" kidneys with secondary reflux had mean ARFI values (6.59 ± 1.45) significantly higher than those with primary reflux (5.35 ± 1.72). CONCLUSIONS: ARFI values decrease from kidneys with secondary vesicoureteral reflux to kidneys with primary reflux to unaffected kidneys contralateral to reflux to normal kidneys.

A rare case of incidental pancreatic arteriovenous malformation correctly diagnosed with MDCT.

CONTEXT: Pancreatic arteriovenous malformations are a rare entity that can be incidentally discovered during MDCT examinations. CASE REPORT: We describe a rare case of asymptomatic arteriovenous malformation presenting at MDCT as a hypervascular mass in the pancreatic head. CONCLUSION: Pancreatic arteriovenous malformations are a rare entity, often asymptomatic, that can be correctly diagnosed by MDCT, especially with the use of specific electronic reconstructions.

Thalamic-insular dysconnectivity in schizophrenia: evidence from structural equation modeling.

Structural and functional studies have shown that schizophrenia is often associated with frontolimbic abnormalities in the prefrontal and mediotemporal regions. It is still unclear, however, if such dysfunctional interaction extends as well to relay regions such as the thalamus and the anterior insula. Here, we measured gray matter volumes of five right-hemisphere regions in 68 patients with schizophrenia and 77 matched healthy subjects. The regions were amygdala, thalamus, and entorhinal cortex (identified as anomalous by prior studies on the same population) and dorsolateral prefrontal cortex and anterior insula (isolated by voxel-based morphometry analysis). We used structural equation modeling and found altered path coefficients connecting the thalamus to the anterior insula, the amygdala to the DLPFC, and the entorhinal cortex to the DLPFC. In particular, patients exhibited a stronger thalamus-insular connection than healthy controls. Instead, controls showed positive entorhinal-DLPFC and negative amygdalar-DLPFC connections, both of which were absent in the clinical population. Our data provide evidence that schizophrenia is characterized by an impaired right-hemisphere network, in which intrahemispheric communication involving relay structures may play a major role in sustaining the pathophysiology of the disease.