Intraprocedural Ablation Margin Assessment by Using Ammonia Perfusion PET during FDG PET/CT-guided Liver Tumor Ablation: A Pilot Study.

Purpose To prospectively determine whether nitrogen 13 (13N) ammonia perfusion positron emission tomography (PET) during fluorine 18 fluorodeoxyglucose (FDG) PET/computed tomography (CT)-guided liver tumor ablation can be used to intraprocedurally assess ablation margins. Materials and Methods Eight patients (five women and three men; age range, 36-74 years; mean age, 57 years) were enrolled in this pilot study and underwent FDG PET/CT-guided microwave ablation of 11 FDG-avid liver metastases (mean diameter, 22 mm; range, 11-34 mm). All procedures were performed between March 2014 and December 2016. Complete ablation margin visibility and minimum ablation margin thickness were assessed by using intraprocedural 13N-ammonia perfusion PET compared with 24-hour postprocedural MR imaging by two independent blinded radiologists. Local tumor progression for each ablated tumor was assessed at follow-up imaging for 3-38 months (median, 17.6 months). Descriptive analysis was performed. Results Eleven of 11 (100%) ablation margins were fully assessable by using intraprocedural perfusion PET by both readers; six of eleven (55%) margins were fully assessable by both readers at postprocedural 24-hour MR imaging. By using perfusion PET, one tumor that had been judged by both readers to have a minimum margin of 0 mm progressed locally. No tumors judged to have a minimum margin greater than 0 mm at perfusion PET progressed locally. Conclusion 13N-ammonia perfusion PET during FDG PET/CT-guided liver tumor ablations can potentially be used to intraprocedurally assess the entire ablation margin, including the minimum margin. © RSNA, 2018.

Interreader Agreement of Prostate Imaging Reporting and Data System Version 2 Using an In-Bore MRI-Guided Prostate Biopsy Cohort: A Single Institution's Initial Experience.

OBJECTIVE: The purpose of this study is to determine the interobserver agreement of the Prostate Imaging Reporting and Data System version 2 (PI-RADSv2) for diagnosing prostate cancer using in-bore MRI-guided prostate biopsy as the reference standard. MATERIALS AND METHODS: Fifty-nine patients underwent in-bore MRI-guided prostate biopsy between January 21, 2010, and August 21, 2013, and underwent diagnostic multiparametric MRI 6 months or less before biopsy. A single index lesion per patient was selected after retrospective review of MR images. Three fellowship-trained abdominal radiologists (with 1-11 years' experience) blinded to clinical information interpreted all studies according to PI-RADSv2. Interobserver agreement was assessed using Cohen kappa statistics. RESULTS: Thirty-eight lesions were in the peripheral zone and 21 were in the transition zone. Cancer was diagnosed in 26 patients (44%). Overall PI-RADS scores were higher for all biopsy-positive lesions (mean ± SD, 3.9 ± 1.1) than for biopsy-negative lesions (3.1 ± 1.0; p < 0.0001) and for clinically significant lesions (4.2 ± 1.0) than for clinically insignificant lesions (3.1 ± 1.0; p < 0.0001). Overall suspicion score interobserver agreement was moderate (κ = 0.45). There was moderate interobserver agreement among overall PI-RADS scores in the peripheral zone (κ = 0.46) and fair agreement in the transition zone (κ = 0.36). CONCLUSION: PI-RADSv2 scores were higher in the biopsy-positive group. PI-RADSv2 showed moderate interobserver agreement among abdominal radiologists with no prior experience using the scoring system.

Bending percutaneous drainage catheters to facilitate CT-guided insertion using curved trocar technique.

PURPOSE: To assess the safety and efficacy of placing thoraco-abdominal drainage catheters under CT-guidance using a curved trocar technique. METHODS: A retrospective study of 182 CT/CT-fluoroscopy-guided thoraco-abdominal catheter drainages was conducted; half were performed by residents or fellows under the supervision of one radiologist (Group 1) and the other half under the supervision of 10 other radiologists (Group 2). Group 1 procedures employed a curved catheter assembly placed using trocar technique (n = 44) or straight catheters placed with Seldinger technique (n = 47). Group 2 procedures employed a straight catheter placed using trocar technique (n = 16) or straight catheters placed with Seldinger technique (n = 75). Technical success, procedure time, radiation dose (CT Dose Index CTDIvol), and adverse events (Common Terminology Criteria for Adverse Events, 4.0) were compared between techniques and groups using Student's t test, Fisher's exact test or Chi-square analysis. RESULTS: All procedures in groups 1 and 2 were technically successful. Mean procedure time for Group 1 curved trocar technique (28 ± 8 min) was shorter than groups 1 and 2 Seldinger technique (37 ± 11 min, p = .00002). Mean CTDIvol for Group 1 curved trocar technique (107.8 ± 54.2 mGy) was lower than groups 1 and 2 Seldinger technique (136.1 ± 99.7 mGy, p = 0.032). Adverse event rates for curved trocar, straight trocar, and Seldinger techniques were 2.3% (1/44), 0% (0/16), and 3.3% (4/122), respectively (p = 1); all were grade 1 or 2, and no catheter malfunctions occurred. CONCLUSIONS: The curved catheter trocar technique is a safe and effective modification of the standard trocar technique that may facilitate CT-guided procedures impeded by CT gantry size limitations.

Hepatobiliary phase MRI: impact on planning image-guided liver tumor ablations.

PURPOSE: To assess the impact of hepatobiliary phase images obtained during intravenous gadoxetate disodium-enhanced liver MRI in the planning of image-guided liver tumor ablations. METHODS: This institutional review board-approved retrospective study included 34 patients (21 men, 13 women, ages 25-80) who underwent 36 liver MRI examinations with gadoxetate disodium within 12 weeks prior to image-guided thermal ablation of 62 liver tumors during 36 procedures. Visibility of bile ducts, subdivided by branch order, on hepatobiliary phase images was compared to standard MRI sequence images by an attending abdominal radiologist and fellow. Interventional decision making (whether or not to ablate and technical plan) using hepatobiliary phase images was compared with standard MRI sequences by the ablationists. The technical success and adverse events of ablation procedures were noted. RESULTS: Bile duct visibility was significantly increased by at least one branch order in 18/36 (50%) examinations (p < 0.0001). Interventional decisions were significantly impacted in 15 (41.7%) of 36 ablation procedures (p < 0.0001), including changes to the technical plan in six (16.7%) of these procedures (p = 0.005). Technical success was achieved for 60/62 (97%) of tumors. Mild (grade 1) adverse events occurred in 4/36 (11%) procedures; no biliary complications occurred. CONCLUSIONS: Use of hepatobiliary phase images obtained during gadoxetate disodium-enhanced liver MRI impacted both when and how to perform image-guided liver tumor ablations in our practice.

Liver health in adults with Fontan circulation: A multicenter cross-sectional study.

OBJECTIVES: Liver disease is an important contributor to morbidity and mortality in patients after Fontan surgery. There has been no large-scale survey of liver health in this population. We sought to explore the prevalence and predictors of liver disease in a multicenter cohort of adults with Fontan physiology. METHODS: Subjects were recruited from 6 adult congenital heart centers. Demographics; clinical history; and laboratory, imaging, and histopathology data were obtained. RESULTS: Of 241 subjects (median age 25.8 years [11.8-59.4], median time since Fontan 20.3 years [5.4-34.5]), more than 94% of those who underwent testing (208 of 221) had at least 1 abnormal liver-related finding. All hepatic imaging (n = 54) and liver histology (n = 68) was abnormal. Subjects with abnormal laboratory values had higher sinusoidal fibrosis stage (2 vs 1, P = .007) and higher portal fibrosis stage (3 vs 1, P = .003) compared with those with all normal values. Low albumin correlated with lower sinusoidal fibrosis stage (1 vs 2; P = .02) and portal fibrosis stage (0 vs 3, P = .002); no other liver studies correlated with fibrosis. Regenerative nodules were seen on 33% of histology specimens. CONCLUSIONS: Regardless of modality, findings of liver disease are common among adults with Fontan circulation, even those appearing clinically well. Cirrhosis is present in up to one-third of subjects. Correlations between hepatic fibrosis stage and clinical history or findings on noninvasive testing are few. Further research is needed to identify patients at risk for more severe liver disease and to determine the best methods for assessing liver health in this population.

Incidence and clinical sequelae of portal and hepatic venous thrombosis following percutaneous cryoablation of liver tumors.

PURPOSE: To assess the incidence and sequelae of portal and hepatic venous thrombosis after percutaneous cryoablation of hepatic tumors. METHODS: From November 1998 through December 2010, 223 hepatic tumors were cryoablated during 170 ablation procedures in 135 patients. 24-h post-procedure MR images were reviewed retrospectively by two abdominal radiologists in consensus to identify tumor ablations that developed one or more new portal or hepatic venous thromboses in or outside the ablation zone. On follow-up MRI and CT examinations the outcomes of thromboses were classified as resolved, partially recanalized, persistent, or propagated. RESULTS: Venous thrombosis developed in association with 54 (24%) of 223 tumor ablations treated during 53 (31%) ablation procedures in 39 (28.8%) patients (15 women, 24 men; age range 40-82 years, mean 59 years). Of these 54 thromboses, 49 (91%) were located in portal vein branches, four (7%) in both portal and hepatic vein branches, and one (2%) in a hepatic vein branch. Thrombosed veins were outside but abutted the ablation zone in 36 (66.7%), and within it in 18 (33.3%). On follow-up imaging (n = 49), thrombi resolved in 29 (59%), partially recanalized in two (4%), persisted in 18 (37%) and propagated from sub-segmental or segmental branches to the left or right portal branches in five (10%). No thrombus propagated to the main portal vein or inferior vena cava. CONCLUSION: Portal and hepatic vein branch thromboses are common in small branches following percutaneous cryoablation of hepatic tumors and most resolve spontaneously without sequelae.

Evaluation of Qualitative Magnetic Resonance Imaging Features for Diagnosis of Chronic Pancreatitis.

OBJECTIVES: The purpose of this study was to determine qualitative pancreatic magnetic resonance imaging (MRI) features that must be present to predict abnormal pancreatic secretory function in patients evaluated for chronic pancreatitis (CP). METHODS: The MRIs of study subjects were reviewed by 2 abdominal radiologists; qualitative parenchyma and ductal features were recorded. Endoscopic pancreatic function test (ePFT) results (reference standard) were classified as normal (peak pancreatic fluid bicarbonate [HCO3-] ≥75 meq/L) or abnormal (<75). Abnormal ePFT was further classified as mild/moderate (74-65) and marked deficiency (<65). Statistical analysis was performed to assess the association between MRI features and abnormal ePFT. RESULTS: The study cohort was composed of 93 subjects, mean age 49 years (range, 18-78 years), 65% females. Univariate analysis identified 9 qualitative MRI features significantly (P < 0.05) associated with abnormal pancreatic secretory function. Number of MRI features increases as peak pancreatic fluid [HCO3-] decreases (Pearson r = -0.629; P = 0.001). Receiver operating characteristic curve analysis determined that a threshold of 6 or more associated MRI features 64% sensitive and 94% specific for marked bicarbonate deficiency. CONCLUSIONS: Qualitative MRI parenchymal and ductal features are associated with CP. Presence of 6 or more features results in a higher specificity for the diagnosis of CP in advanced disease.

Impact of a Structured Report Template on the Quality of MRI Reports for Rectal Cancer Staging.

OBJECTIVE: The purpose of this study is to assess the impact of implementing a structured report template on the quality of MRI reports for rectal cancer staging. MATERIALS AND METHODS: After excluding examinations performed after surgery or neoadjuvant therapy, we analyzed all rectal cancer staging MRI reports finalized at an academic medical center 12 months before and after an intervention consisting of implementing a structured report template integrated into the institution's speech recognition system. The primary outcome measure was the quality of rectal cancer staging MRI reports classified as optimal, satisfactory, or unsatisfactory, on the basis of the documentation of 14 quality measures predefined by a consensus of the institution's abdominal radiology subspecialists. Chi-square and t tests were used to assess differences in report quality and documentation of each discrete quality measure before and after the intervention. RESULTS: The study cohort included 106 MRI reports from 104 patients (mean age, 60 years; 58.5% male); 52 (49.1%) of the reports were completed before implementation of the structured report template. After implementation, the proportion of total reports classified as optimal or satisfactory increased from 38.5% (20/52) to 70.4% (38/54) (p = 0.0010). No reports generated before the intervention were classified as optimal, whereas 40.7% (22/54) of reports were classified as optimal after the intervention. CONCLUSION: Implementation and voluntary use of a structured report template improved the quality of MRI reports for rectal cancer staging compared with free-text format.

Impact of an Information Technology-Enabled Initiative on the Quality of Prostate Multiparametric MRI Reports.

RATIONALE AND OBJECTIVES: Assess the impact of implementing a structured report template and a computer-aided diagnosis (CAD) tool on the quality of prostate multiparametric magnetic resonance imaging (mp-MRI) reports. MATERIALS AND METHODS: Institutional Review Board approval was obtained for this Health Insurance Portability and Accountability Act-compliant study performed at an academic medical center. The study cohort included all prostate mp-MRI reports (n = 385) finalized 6 months before and after implementation of a structured report template and a CAD tool (collectively the information technology [IT] tools) integrated into the picture archiving and communication system workstation. Primary outcome measure was quality of prostate mp-MRI reports. An expert panel of our institution's subspecialty-trained abdominal radiologists defined prostate mp-MRI report quality as optimal, satisfactory, or unsatisfactory based on documentation of nine variables. Reports were reviewed to extract the predefined quality variables and determine whether the IT tools were used to create each report. Chi-square and Student's t tests were used to compare report quality before and after implementation of IT tools. RESULTS: The overall proportion of optimal or satisfactory reports increased from 29.8% (47/158) to 53.3% (121/227) (P < .001) after implementing the IT tools. Although the proportion of optimal or satisfactory reports increased among reports generated using at least one of the IT tools (47/158 = [29.8%] vs. 105/161 = [65.2%]; P < .001), there was no change in quality among reports generated without use of the IT tools (47/158 = [29.8%] vs. 16/66 = [24.2%]; P = .404). CONCLUSIONS: The use of a structured template and CAD tool improved the quality of prostate mp-MRI reports compared to free-text report format and subjective measurement of contrast enhancement kinetic curve.

Radiogenomics of clear cell renal cell carcinoma: preliminary findings of The Cancer Genome Atlas-Renal Cell Carcinoma (TCGA-RCC) Imaging Research Group.

PURPOSE: To investigate associations between imaging features and mutational status of clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: This multi-institutional, multi-reader study included 103 patients (77 men; median age 59 years, range 34-79) with ccRCC examined with CT in 81 patients, MRI in 19, and both CT and MRI in three; images were downloaded from The Cancer Imaging Archive, an NCI-funded project for genome-mapping and analyses. Imaging features [size (mm), margin (well-defined or ill-defined), composition (solid or cystic), necrosis (for solid tumors: 0%, 1%-33%, 34%-66% or >66%), growth pattern (endophytic, <50% exophytic, or ≥50% exophytic), and calcification (present, absent, or indeterminate)] were reviewed independently by three readers blinded to mutational data. The association of imaging features with mutational status (VHL, BAP1, PBRM1, SETD2, KDM5C, and MUC4) was assessed. RESULTS: Median tumor size was 49 mm (range 14-162 mm), 73 (71%) tumors had well-defined margins, 98 (95%) tumors were solid, 95 (92%) showed presence of necrosis, 46 (45%) had ≥50% exophytic component, and 18 (19.8%) had calcification. VHL (n = 52) and PBRM1 (n = 24) were the most common mutations. BAP1 mutation was associated with ill-defined margin and presence of calcification (p = 0.02 and 0.002, respectively, Pearson's χ (2) test); MUC4 mutation was associated with an exophytic growth pattern (p = 0.002, Mann-Whitney U test). CONCLUSIONS: BAP1 mutation was associated with ill-defined tumor margins and presence of calcification; MUC4 mutation was associated with exophytic growth. Given the known prognostic implications of BAP1 and MUC4 mutations, these results support using radiogenomics to aid in prognostication and management.

Necrotizing pancreatitis: diagnosis, imaging, and intervention.

Acute necrotizing pancreatitis is a severe form of acute pancreatitis characterized by necrosis in and around the pancreas and is associated with high rates of morbidity and mortality. Although acute interstitial edematous pancreatitis is diagnosed primarily on the basis of signs, symptoms, and laboratory test findings, the diagnosis and severity assessment of acute necrotizing pancreatitis are based in large part on imaging findings. On the basis of the revised Atlanta classification system of 2012, necrotizing pancreatitis is subdivided anatomically into parenchymal, peripancreatic, and combined subtypes, and temporally into clinical early (within 1 week of onset) and late (>1 week after onset) phases. Associated collections are categorized as "acute necrotic" or "walled off" and can be sterile or infected. Imaging, primarily computed tomography and magnetic resonance imaging, plays an essential role in the diagnosis of necrotizing pancreatitis and the identification of complications, including infection, bowel and biliary obstruction, hemorrhage, pseudoaneurysm formation, and venous thrombosis. Imaging is also used to help triage patients and guide both temporizing and definitive management. A "step-up" method for the management of necrotizing pancreatitis that makes use of imaging-guided percutaneous catheter drainage of fluid collections prior to endoscopic or surgical necrosectomy has been shown to improve clinical outcomes. The authors present an algorithmic approach to the care of patients with necrotizing pancreatitis and review the use of imaging and interventional techniques in the diagnosis and management of this pathologic condition.

Computed tomography-guided percutaneous biopsy of isoattenuating focal liver lesions.

PURPOSE: The purpose of this study was to evaluate the efficacy of CT-guided percutaneous biopsy of isoattenuating liver lesions using anatomic landmarks (ALs) to guide needle placement and added value of intravenous (IV) contrast. METHODS: An interventional radiology database was reviewed to identify patients with CT-guided percutaneous biopsy of isoattenuating focal liver lesions using ALs to guide needle placement. The cohort was further divided into two groups: lesions biopsied using ALs only and lesions biopsied using ALs and intravenous contrast (AL+IV). Pathology results or follow-up imaging served as reference standard. Sensitivity and accuracy were calculated, Student's t test and Fisher's exact test were used for statistical comparison between the two groups. RESULTS: Between January 2000 and December 2011, CT-guided percutaneous biopsy of 133 isoattenuating focal liver lesions was performed in 133 patients. The AL group included 54 patients (M:F = 29:25) with 54 lesions (size range 7-90 mm, mean 32.1 ± 18.1) and AL+IV group included 79 patients (M:F = 44:35) with 79 lesions (size range 7-100 mm, mean 25.6 ± 15.0). AL group included 23 (43%) benign and 31 (57%) malignant lesions; AL+IV group included 31 (39%) benign and 48 (61%) malignant lesions. Sensitivity and accuracy for CT-guided biopsy of focal isoattenuating liver lesions were, overall 94% and 96%, AL group 97% and 98% and AL+IV group 92% and 94%, with no statistical significant difference between the AL and AL+IV groups (P = 0.88-1.00). CONCLUSION: Accurate planning and utilizing of internal reference ALs is successful in yielding a diagnostic sample for CT-guided percutaneous biopsy of isoattenuating focal liver lesion. The confidence of accurate targeting can be enhanced by administering IV contrast, however, since the visualization provided by IV contrast can be short-lived; use of IV contrast does not obviate the need for precise planning based on ALs.

Successful percutaneous radiologic management of renal cell carcinoma tumor seeding caused by percutaneous biopsy performed before ablation.

A case is reported of the successful image-based detection, diagnosis, and percutaneous ablation of tumor seeding in a 61-year-old man that was caused by percutaneous biopsy of a renal cell carcinoma performed before cryoablation and was not detected until 4 years after the biopsy procedure. Although tumor seeding is a rare complication after percutaneous biopsy or ablation, this case emphasizes the importance of imaging surveillance of the needle tract used during both biopsy and ablation procedures, provides guidance on measures that can be used to minimize the occurrence of tumor seeding, and demonstrates that entirely radiologic management can be successful.

The challenging image-guided abdominal mass biopsy: established and emerging techniques 'if you can see it, you can biopsy it'.

Image-guided percutaneous biopsy of abdominal masses is among the most commonly performed procedures in interventional radiology. While most abdominal masses are readily amenable to percutaneous biopsy, some may be technically challenging for a number of reasons. Low lesion conspicuity, small size, overlying or intervening structures, motion, such as that due to respiration, are some of the factors that can influence the ability and ultimately the success of an abdominal biopsy. Various techniques or technologies, such as choice of imaging modality, use of intravenous contrast and anatomic landmarks, patient positioning, organ displacement or trans-organ approach, angling CT gantry, triangulation method, real-time guidance with CT fluoroscopy or ultrasound, sedation or breath-hold, pre-procedural image fusion, electromagnetic tracking, and others, when used singularly or in combination, can overcome these challenges to facilitate needle placement in abdominal masses that otherwise would be considered not amenable to percutaneous biopsy. Familiarity and awareness of these techniques allows the interventional radiologist to expand the use of percutaneous biopsy in clinical practice, and help choose the most appropriate technique for a particular patient.

Mono-belly and beyond: spectrum of imaging manifestations of EBV infection in the abdomen.

Epstein-Barr virus (EBV) is a DNA virus from the herpes virus group affecting only humans. More than 90% adults are infected by the virus, but very few ever have symptoms. Within the abdomen, both solid and hollow viscera can be involved in symptomatic disease. Awareness of the spectrum of imaging findings, high index of suspicion, and appropriate clinical and laboratory information can help in the early and accurate diagnosis in these cases.

Cigarette smoking impairs pancreatic duct cell bicarbonate secretion.

OBJECTIVE: To compare pancreatic duct cell function in smokers (current and past) and never smokers by measurement of secretin-stimulated peak bicarbonate concentration ([HCO3-]) in endoscopic collected pancreatic fluid (PF). METHODS: This retrospective study was cross-sectional in design, recording demographic information (age, gender, etc.), smoking status (former, current, never), alcohol intake, clinical data (imaging, endoscopy), and laboratory results (peak PF [HCO3-]) from subjects evaluated for pancreatic disease at a tertiary pancreas center. Univariate and multivariate statistical analysis (SAS Version 9.2, Cary, NC, USA) was performed to assess the relationship between cigarette smoking and secretin-stimulated pancreatic fluid bicarbonate concentration. RESULTS: A total of 131 subjects underwent pancreatic fluid collection (endoscopic pancreatic function test, ePFT) for bicarbonate analysis: 25.2% (33 out of 131) past smokers, 31.3% (41 out of 131) current smokers, and 43.5% (57 out of 131) were never smokers. Measures of Association: The mean peak PF [HCO3-] in never smokers (81.3 ± 18.5 mEq/L) was statistically higher (indicating better duct cell function) when compared to past smokers (66.8 ± 24.7 mEq/L, P=0.005) and current smokers (70.0 ± 20.2 mEq/L, P=0.005). However, the mean peak [HCO3-] in past smokers was not statistically different from that in current smokers (P=0.575), and therefore, the two smoking groups were combined to form a single "smokers cohort". When compared to the never smokers, the smokers cohort was older (P=0.037) and had a greater proportion of subjects with definite chronic pancreatitis imaging (P=0.010), alcohol consumption ≥20 g/day (P=0.012), and abnormal peak PF [HCO3-] (P<0.001). Risk-Based Estimates: Cigarette smoking (risk ratio, RR: 2.2, 95% CI: 1.3-3.5; P<0.001), diagnosis of definite chronic pancreatitis imaging (RR: 2.2, 95% CI: 1.6-3.2; P<0.001) and alcohol consumption ≥20 g/day (RR: 1.6, 95% CI: 1.1-2.4; P=0.033) were all associated with low mean peak PF [HCO3-] (indicating duct cell secretory dysfunction). Multivariate Analysis: Smoking (odds ratio, OR: 3.8, 95% CI: 1.6-9.1; P=0.003) and definite chronic pancreatitis imaging (OR: 5.7, 95% CI: 2.2-14.8; P<0.001) were determined to be independent predictors of low peak PF [HCO3-], controlling for age, gender, and alcohol intake. Furthermore there was no interaction between smoking status and alcohol intake in predicting duct cell dysfunction (P=0.571). CONCLUSION: Measurement of pancreatic fluid bicarbonate in smokers reveals that cigarette smoking (past and current) is an independent risk factor for pancreatic duct cell secretory dysfunction (low PF [HCO3-]). Furthermore, the risk of duct cell dysfunction in subjects who smoked was approximately twice the risk (RR: 2.2) in never smokers. Further in depth, translational research approaches to pancreatic fluid analysis may help unravel mechanisms of cigarette smoking induced pancreatic duct cell injury.

Imaging after percutaneous radiofrequency ablation of hepatic tumors: Part 1, Normal findings.

OBJECTIVE: The purpose of this article is to review the spectrum of early and delayed normal cross-sectional imaging findings after percutaneous radiofrequency ablation of hepatic tumors. CONCLUSION: Knowledge of postablation imaging changes is vital not only for the interventionalist who performs the procedure but also for the diagnostician who interprets the postablation imaging. Recognition of normal postprocedural changes and differentiation from abnormal imaging findings prevent overcalling benign changes as abnormal and can thus avoid needless treatment.

Imaging after percutaneous radiofrequency ablation of hepatic tumors: Part 2, Abnormal findings.

OBJECTIVE: The purpose of this article is to review the spectrum of early and delayed abnormal cross-sectional imaging findings after radiofrequency ablation (RFA) of hepatic tumors. CONCLUSION: Recognition of abnormal post-RFA imaging findings and differentiation of abnormal findings from normal postprocedural changes are important for diagnostic and interventional radiologists. Early identification of residual or recurrent disease and complications can facilitate timely retreatment, management, and follow-up care.

Inflammatory protein profiling of pancreatic cyst fluid using EUS-FNA in tandem with cytokine microarray differentiates between branch duct IPMN and inflammatory cysts.

BACKGROUND: Diagnosis of pancreatic cystic neoplasms remains problematic. We hypothesize that inflammatory mediator proteins in pancreatic cyst fluid can differentiate branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) and pancreatic inflammatory cysts. We aim to 1) detect inflammatory mediator proteins (IMPs) using a multiplexed IMP-targeted microarray in pancreatic cyst fluid obtained during endoscopic ultrasound fine needle aspiration (EUS-FNA) and 2) compare IMP profiles in pancreatic cyst fluid from BD-IPMNs and inflammatory cysts. Pancreatic cyst fluid from ten patients (5 BD-IPMN and 5 inflammatory cysts) was obtained by EUS-FNA and analyzed directly with a multiplexed microarray assay to determine concentrations of 89 IMPs. Statistical analysis was performed using non-parametric methods. RESULTS: Eighty-three of the 89 assayed IMPs were detected in at least one of the 10 patient samples. Seven IMPs were detected in BD-IPMN but not inflammatory cysts, while eleven IMPs were identified in inflammatory cysts but not BD-IPMN. Notably, granulocyte-macrophage colony-stimulating factor (GM-CSF) expression was present in all five inflammatory cyst samples. Hepatocyte growth factor (HGF) was present in significantly higher concentrations in inflammatory cysts compared to BD-IPMN. CONCLUSION: Our exploratory analysis reveals that GM-CSF and HGF in EUS-FNA-collected pancreatic cyst fluid can distinguish between BD-IPMN and inflammatory cyst. Coupling microarray molecular techniques to EUS-FNA may represent a major step forward to our understanding complex pancreatic disease.

Imaging of chronic pancreatitis (including groove and autoimmune pancreatitis).

Multiple disorders may cause chronic pancreatitis (CP) through recurrent inflammation of the pancreatic parenchyma. Chronic calcifying pancreatitis caused by excessive alcohol intake accounts for most cases of CP. However, there are multiple other causes of CP, including obstructive chronic pancreatitis, autoimmune pancreatitis, groove pancreatitis, tropical, and hereditary pancreatitis. This article reviews the multiple imaging techniques, some of which are accepted as first-line modalities in patients with suspected CP, and the imaging features associated with the different causes of CP.