Interobserver Variability in CT-based Morphologic Tumor Response Assessment of Colorectal Liver Metastases.

Purpose To evaluate interobserver variability in the morphologic tumor response assessment of colorectal liver metastases (CRLM) managed with systemic therapy and to assess the relation of morphologic response with gene mutation status, targeted therapy, and Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 measurements. Materials and Methods Participants with initially unresectable CRLM receiving different systemic therapy regimens from the randomized, controlled CAIRO5 trial (NCT02162563) were included in this prospective imaging study. Three radiologists independently assessed morphologic tumor response on baseline and first follow-up CT scans according to previously published criteria. Two additional radiologists evaluated disagreement cases. Interobserver agreement was calculated by using Fleiss κ. On the basis of the majority of individual radiologic assessments, the final morphologic tumor response was determined. Finally, the relation of morphologic tumor response and clinical prognostic parameters was assessed. Results In total, 153 participants (median age, 63 years [IQR, 56-71]; 101 men) with 306 CT scans comprising 2192 CRLM were included. Morphologic assessment performed by the three radiologists yielded 86 (56%) agreement cases and 67 (44%) disagreement cases (including four major disagreement cases). Overall interobserver agreement between the panel radiologists on morphology groups and morphologic response categories was moderate (κ = 0.53, 95% CI: 0.48, 0.58 and κ = 0.54, 95% CI: 0.47, 0.60). Optimal morphologic response was particularly observed in patients treated with bevacizumab (P = .001) and in patients with RAS/BRAF mutation (P = .04). No evidence of a relationship between RECIST 1.1 and morphologic response was found (P = .61). Conclusion Morphologic tumor response assessment following systemic therapy in participants with CRLM demonstrated considerable interobserver variability. Keywords: Tumor Response, Observer Performance, CT, Liver, Metastases, Oncology, Abdomen/Gastrointestinal Clinical trial registration no. NCT02162563 Supplemental material is available for this article. © RSNA, 2022.

Multidetector computed tomography assessment of vascular involvement in perihilar cholangiocarcinoma.

BACKGROUND: In approximately 40% of patients with perihilar cholangiocarcinoma (PHC), the tumor is deemed unresectable at laparotomy, often due to vascular involvement. On imaging, occlusion, narrowing, wall irregularity and >180° tumor-vessel contact have been suggested to predict vascular involvement in patients with PHC. The objective of this study was to correlate computed tomography (CT) findings in PHC with surgical and histopathological results, in order to evaluate the accuracy of currently used CT criteria for vascular involvement. METHODS: Patients with PHC undergoing exploration in a single tertiary center (2015-2018) were included. Tumor-vessel relation of portal vein and hepatic artery on CT were scored by two independent radiologists, blinded for surgical and pathological outcomes. Intraoperative findings were scored by the surgeon in theatre or derived from operation/pathology reports. RESULTS: A total of 42 CT scans were evaluated, resulting in assessment of 115 vessels. Portal vein occlusion, narrowing and presence of an irregular wall on CT corresponded with a positive predictive value (PPV) for involvement of 100%, 83% and 75%, respectively. For the hepatic artery, PPV of occlusion and stenosis was 100%, whilst other criteria had PPV <70%. Combining potential criteria (>180° contact, narrowing, irregularity or occlusion) resulted in PPV, sensitivity and specificity of 85%, 67% and 94%, respectively, for the portal vein and 53%, 40% and 75%, respectively, for the hepatic artery. CONCLUSIONS: Prediction of vascular involvement on CT is more difficult for the hepatic artery than for the portal vein. Suggestion of hepatic artery invasion on imaging, other than occlusion or stenosis, should not preclude surgical exploration.

Staging Laparoscopy in Patients with Intrahepatic Cholangiocarcinoma: Is It Still Useful?

BACKGROUND: The role of staging laparoscopy in patients with intrahepatic cholangiocarcinoma remains unclear. Despite extensive preoperative imaging, approximately 25% of patients are deemed unresectable at laparotomy due to metastasized disease. The aim of this study was to evaluate the frequency of unresectable disease found at staging laparoscopy and to identify predictors for detecting metastasized intrahepatic cholangiocarcinoma. METHODS: We retrospectively collected records of all patients with intrahepatic cholangiocarcinoma, presenting at our institution from 2008 to 2017. Staging laparoscopy was performed on the suspicion of distant metastases and on indication in larger tumors. The yield and sensitivity of staging laparoscopy was calculated. Reasons for unresectability at staging laparoscopy or laparotomy were recorded. RESULTS: Among a total of 80 patients with potentially resectable intrahepatic cholangiocarcinoma, 35 patients underwent staging laparoscopy on the suspicion of distant metastases. Unresectable disease was found at staging laparoscopy in 15 patients. Reasons for unresectability were liver metastasis (n = 6), peritoneal metastasis (n = 4), severe cirrhosis (n = 2), locally advanced tumor with satellite lesions (n = 1), and distant lymph node metastasis (n = 2). Considering optimal preoperative imaging, the true yield of staging laparoscopy was 20% (7/35). Two patients did not undergo laparotomy due to progression after staging laparoscopy. Of the remaining 18 patients who underwent laparotomy, 6 patients (30%) had unresectable disease, mostly because of distant metastasis (n = 4). CONCLUSIONS: The role of staging laparoscopy to detect unresectable intrahepatic cholangiocarcinoma is highly dependent on the quality of preoperative imaging. Currently, no accurate selection criteria on imaging exist to select patients with intrahepatic cholangiocarcinoma who potentially benefit from staging laparoscopy.

Impact of expanding indications on surgical and oncological outcome in 1434 consecutive pancreatoduodenectomies.

BACKGROUND: Over the years, high-volume pancreatic centers expanded their indications for pancreatoduodenectomy (PD) but with unknown impact on surgical and oncological outcome. METHODS: All consecutive PDs performed between 1992-2017 in a single pancreatic center were identified from a prospectively maintained database and analyzed according to three time periods. RESULTS: In total, 1434 patients underwent PD. Over time, more elderly patients underwent PD (P < 0.001) with increased use of vascular resection (10.4 to 16.0%, P < 0.001). In patients with cancer (n = 1049, 74.8%), the proportion pT3/T4 tumors increased from 54.3% to 70.6% over time (P < 0.001). The postoperative pancreatic fistula (16.0%), postpancreatectomy hemorrhage (8.0%) and delayed gastric emptying (31.0%) rate did not reduce over time, whereas median length of stay decreased from 16 to 12 days (P < 0.001). The overall failure-to-rescue rate (6.9%) and in-hospital mortality (2.2%) remained stable (P = 0.89 and P = 0.45). In 523 patients with pancreatic cancer (36.5%), the use of both adjuvant and neoadjuvant chemotherapy increased over time (both p<0.001), and the five-year overall survival improved from 11.0% to 17.4% (P < 0.001). CONCLUSIONS: In a period where indications for PD expanded, with more elderly patients, more advanced cancers and increased use of vascular resections, surgical outcome remained favorable and five-year survival for pancreatic cancer improved.

Two Cases of Hepatoblastoma in Young Adults.

Adult hepatoblastoma (AHB) is a rare liver tumor with a poor prognosis in adolescents and adults. This contrasts with hepatoblastoma in children and is not fully understood. Here we describe two adolescents with AHB who were treated in our hospital. Adolescents are likely to receive less intensive chemotherapy protocols and are treated in hospitals with less experience in pediatric oncology, resulting in poor outcome. More research is necessary for optimal treatment of AHB in adolescents. Adolescents with AHB should be referred to hospitals experienced in pediatric oncology and receive intensive chemotherapy, followed by hemihepatectomy.

Hepatic epithelioid haemangioendothelioma (HEHE): a diagnostic dilemma between haemangioma and angiosarcoma.

We present a case of a 77-year-old male patient with a liver tumour diagnosed as hepatic epithelioid haemangioendothelioma (HEHE), a potentially malignant tumour treated with liver resection. The patient is disease-free 3 years after resection. Imaging features using fludeoxyglucose F 18 positron emission tomography CT and MRI with gadoxic acid as well as histopathological findings are discussed.

The vanishing duodenal polyp: mesenteric invagination presenting as duodenal pseudopolyp.

Duodenal polypoid masses are an uncommon finding mainly diagnosed incidentally at endoscopy or surgery. We report a 39-year-old female patient with symptoms of intermittent stabbing pain in the upper right abdominal quadrant and an iron deficiency anaemia, without complaints of weight loss, haematemesis or melaena. A duodenal polyp and acute duodenitis have been described during endoscopic examinations and CT and ultrasound. Surgical excision of the polyp was advised. Intraoperatively, an elongated duodenum was remarkable; however, at duodenotomy, no polyp was found, nor during intraoperative endoscopy. Looking back at the endoscopy and imaging results, it was noted that the polyp varied in size and location. It was therefore concluded that we dealt with the pseudopolyp phenomenon, caused by invagination of the duodenal wall and its mesentery into the duodenum, presenting as a lipomatous pseudopolyp. Telescopic invagination of the duodenal wall was facilitated by the elongated hypermobile duodenum.

Impact of Organic Cation Transporters (OCT-SLC22A) on Differential Diagnosis of Intrahepatic Lesions.

Positron emission tomography (PET) using the cationic compound [18F]fluoromethylcholine (FCH) enhances the sensitivity for noninvasive classification of hepatic tumors due to peculiar patterns of accumulation. The underlying transporters are not known. We aim to identify the carriers mediating uptake of FCH in liver and to correlate their expression pattern with PET intrahepatic signal distribution to clarify the role of membrane transporters in FCH accumulation. FCH transport was characterized in cells overexpressing organic cation transporters (OCTs). OCT mRNA levels were determined in different types of hepatic lesions and correlated with FCH PET signal intensity. Additionally, OCT1 and OCT3 protein was analyzed in a subset of patients by Western blotting. HEK293 cells overexpressing OCT1, OCT2, or OCT3 showed higher intracellular levels of FCH in comparison with wild-type cells. mRNA levels of OCT1 paralleled protein levels and were significantly downregulated in hepatocellular carcinoma (HCC), hepatocellular adenoma (HCA), and, to a lesser extent, in focal nodular hyperplasia compared with matched nontumor tissues. In three patients with HCA, the FCH PET signal intensity was reduced relative to normal liver. This correlated with the simultaneous downregulation of OCT1 and OCT3 mRNA. In another patient with HCA, lesion and surrounding tissue did not show a difference in signal, coinciding with downregulation of OCT1 and upregulation of OCT3. Therefore, OCT1 is very likely a key transporter for the accumulation of FCH in the liver. The data support the hypothesis that the varying expression levels of OCT1 and OCT3 in focal liver lesions determine FCH PET signal intensity.

Long-term outcomes of resection in patients with symptomatic benign liver tumours.

BACKGROUND: Benign liver tumours (e.g., hepatocellular adenoma (HCA), focal nodular hyperplasia (FNH), and haemangioma) are occasionally resected for alleged symptoms, although data on long-term outcomes is lacking. The aim of this cross-sectional study was to assess long-term outcomes of surgical intervention. METHODS: Forty patients with benign tumours (HCA 20, FNH 12, giant haemangioma 4, cysts 4) were included. Patients filled in Validated McGill Pain Questionnaires, preoperatively and after a median of 54 months after resection. Outcomes were evaluated using paired sample t-test and (M) ANOVA. RESULTS: Relief of symptoms sustained in 30/40 patients, within a follow-up of 54 (24-148) months after resection. VAS scores were reduced from 5.5 preoperatively to 1.6 postoperatively (p < 0.001). Patients with left-sided tumours had higher postoperative Pain Rating Index (PRI), compared to patients with right-sided tumours: 15.3 vs. 5.8 (p = 0.018). If patients could reconsider undergoing surgery, 34/38 would again choose resection. Discomfort at the operative scar was the most common complaint: 8/40 patients, all after open surgery, of whom 3/40 had an incisional hernia. 7/40 patients had a laparoscopic resection. CONCLUSION: Resection relieved symptoms in 30/40 patients. The operative scar was a frequent source for remaining postoperative complaints, suggesting an advantage for a laparoscopic approach when feasible.

Screw needle cytology of thyroid nodules is associated with a lower non-diagnostic rate compared to fine needle aspiration.

BACKGROUND: Fine needle aspiration (FNA) cytology is the method of choice to exclude malignancy in thyroid nodules. A major limitation of thyroid FNA is the relatively high rate (13-17%) of non-diagnostic samples. The aim of this study is to determine the diagnostic yield of a screw needle compared to the conventional FNA. METHODS: We retrospectively analysed thyroid nodule cytology of all patients that underwent thyroid nodule fine needle or screw needle aspiration between July 2007 and July 2012 in a single academic medical centre. Cytology results were categorized according to the Bethesda classification system. RESULTS: In total, 644 punctures of thyroid nodules from 459 patients were available for analysis. The screw needle was used 531 times, and the conventional fine needle 113 times. The percentage of non-diagnostic cytology was significantly lower in the screw needle samples than in the fine needle samples (3% vs 17%, P<0.001). CONCLUSION: This study shows a significantly better diagnostic performance of the screw needle compared to the conventional fine needle in cytology of thyroid nodules.

Outcomes of liver resection in hepatocellular adenoma and focal nodular hyperplasia.

OBJECTIVES: The clinical management of hepatocellular adenoma (HCA) and focal nodular hyperplasia (FNH) is still subject to controversy, especially with respect to patient selection for surgery. The aim of this prospective cohort study was to assess the outcomes of surgical intervention. METHODS: Between January 2008 and September 2012, patients diagnosed with FNH or HCA based on magnetic resonance imaging or computed tomography were enrolled in this prospective study. Resection was undertaken in patients with HCA of > 5 cm or symptomatic lesions. Lesion characteristics, extent of liver resection (minor: fewer than three segments; major: three or more segments), morbidity (by Dindo-Clavien class), mortality, postoperative length of stay and symptoms [McGill Pain Questionnaire, including a visual analogue scale (VAS)] were evaluated. RESULTS: A total of 110 patients (106 female; median age: 39 years) were included; 51 patients had HCA and 59 had FNH. Of the 110 patients, 49 underwent resection (33 HCA patients; 16 FNH patients). Laparoscopic minor resection was performed in five HCA and five FNH patients; open minor resection was performed in 19 HCA and seven FNH patients, and open major resection was performed in nine HCA and four FNH patients. Severe postoperative complications were observed in four patients (Grade III, n = 3; Grade IV, n = 1). Median baseline scores on the VAS were 6 in FNH patients and 7 in HCA patients; the median VAS score after resection was 0 (P = 0.008). CONCLUSIONS: If patients with HCA and FNH require surgery, limited resection can be carried out with low morbidity and without mortality. Patients with preoperative symptoms show a high rate of postoperative symptom relief.

Diagnostic accuracy of (18) F-methylcholine positron emission tomography/computed tomography for intra- and extrahepatic hepatocellular carcinoma.

UNLABELLED: Diagnosis of hepatocellular carcinoma (HCC) primarily involves imaging. The aim of this study was to assess the accuracy of (18) F-fluorocholine ((18) F-FCH) positron emission tomography (PET) for detection of HCC and evaluation of extent of disease. Patients with HCC >1 cm were included between 2009 and July 2011, and follow-up closed in February 2013. Diagnosis was based on American Association for the Study of Liver Diseases criteria, and all patients underwent (18) F-FCH PET/computed tomography (CT) at baseline before treatment, 6 underwent a second PET/CT posttreatment, and 1 a third during follow-up. Whole-body PET and low-dose CT imaging were performed 15 minutes after (18) F-FCH injection. Evaluation of imaging was done with standardized uptake value (SUV) ratios: SUV maximum of the lesion divided by the SUV mean of surrounding tissue. Statistical analyses included descriptive analyses, receiver operating characteristic curve, McNemar's test, and Kaplan-Meier's test at 5% level of significance. Twenty-nine patients revealed 53 intrahepatic lesions. In 48 of 53 lesions, (18) F-FCH PET was positive (SUVratio , 1.95 ± 0.66; sensitivity, 88%; specificity, 100%). PET/CT showed uptake in 18 extrahepatic lesions and no uptake in 3 lesions affirmed non-HCC lesions; all lesions were confirmed with additional investigation (accuracy, 100%). In 17 of 29 patients, additional lesions were found on PET/CT imaging, with implications for treatment in 15 patients. Posttreatment PET/CT showed identical results, compared with standard treatment evaluation. CONCLUSION: This study shows additional value of (18) F-FCH PET/CT for patients with HCC. (18) F-FCH PET/CT has implications for staging, management, and treatment evaluation because of accurate assessment of extrahepatic disease.

Von Meyenburg complexes mimicking metastatic disease at laparotomy for focal nodular hyperplasia.

A 44-year-old woman presented with symptoms of fatigue and increasing abdominal discomfort. MRI with the hepatobiliary contrast Gd-EOB-DTPA (Primovist) was performed showing a 6 cm lesion in segment 2/3 of the liver typical for focal nodular hyperplasia (FNH). Because of severe complaints attributed to the lesion, the patient was scheduled for resection. At laparotomy multiple small white lesions were found throughout the liver with enlarged locoregional lymph nodes. Macroscopically, the findings could be consistent with widespread metastases and the surgeon felt compelled to determine the nature of these lesions before continuing resection. Final diagnosis revealed multiple bile duct hamartomas and an FNH lesion as was expected.

The use of 18F-fluoromethylcholine PET/CT in differentiating focal nodular hyperplasia from hepatocellular adenoma: a prospective study of diagnostic accuracy.

INTRODUCTION: Diagnosis of focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) using conventional imaging techniques can be difficult; however, it is important to differentiate between them as these benign liver tumors require different therapeutic strategies. The aim of our study was to prospectively evaluate the use of PET/computed tomography (CT) with F-fluoromethylcholine (F-FCH) as a novel diagnostic approach in the differentiation between HCA and FNH. MATERIALS AND METHODS: Fifty-six consecutive patients with a suspicion of one or multiple HCAs or FNHs larger than 2 cm were prospectively included after written informed consent was obtained from them. All the patients underwent a PET/CT with F-FCH. Histopathology of the lesions was the standard of reference. The ratio of the standardized uptake value (SUV) of the lesions compared with normal liver uptake within the same patient was calculated. Statistical tests were evaluated at the 95% confidence interval. RESULTS: Forty-nine patients with 60 lesions and histopathological diagnosis of FNH or HCA completed the study and were analyzed. The mean SUV ratio for FNH was 1.67±0.31 (mean±SD, n=28), resulting in a positive likelihood ratio of 32.3 for PET-positive FNH. The mean SUV ratio for HCA was 0.82±0.17 (n=32), with a likelihood ratio of ∼100 for PET-negative HCA. Receiver operating characteristic curve analysis revealed an optimal SUV ratio cutoff value of 1.13, which reached 100% sensitivity and 97% specificity in differentiating FNH from HCA. CONCLUSION: This prospective study shows that PET/CT with F-FCH can accurately differentiate FNH from HCA and may become a valuable diagnostic tool when conventional imaging techniques fail to do so.

Diagnostic accuracy of MRI in differentiating hepatocellular adenoma from focal nodular hyperplasia: prospective study of the additional value of gadoxetate disodium.

OBJECTIVE: The purpose of this article is to prospectively determine the sensitivity of hepatobiliary phase gadoxetate disodium-enhanced MRI combined with standard MRI in differentiating focal nodular hyperplasia (FNH) from hepatocellular adenoma (HCA). SUBJECTS AND METHODS: Patients suspected of having FNH or HCA larger than 2 cm underwent gadoxetate disodium-enhanced MRI. Standard MRI was evaluated separately from the additional hepatobiliary phase by two blinded radiologists. For the largest lesion in each patient, findings were compared with histologic diagnosis. Sensitivity, positive predictive value (PPV), and distinctive features were analyzed using McNemar and analysis of variance tests. RESULTS: Fifty-two patients completed the study. Histologic diagnosis revealed 24 HCAs and 28 FNHs. Characterization on standard MRI was inconclusive in 40% (21/52) and conclusive in 60% (31/52) of lesions. The sensitivity of standard MRI for HCA was 50% (12/24) with a PPV of 100% (12/12). The sensitivity for FNH was 68% (19/28) with a PPV of 95% (18/19). After review of hepatobiliary phase, the sensitivity for HCA improved to 96% (23/24) with a PPV of 96% (23/24). The sensitivity for FNH improved to 96% (27/28) with a PPV of 96% (27/28). Features with significant predictive value for diagnosis in HCA included bleeding (p < 0.001), fat (p = 0.010), and glycogen (p = 0.024). The presence of a central scar was predictive for FNH (p < 0.001). CONCLUSION: This study shows high sensitivity of gadoxetate disodium-enhanced MRI when standard series are combined with the hepatobiliary phase for differentiation of FNH and HCA in lesions larger than 2 cm.

Disappointing interobserver agreement among radiologists for a classifying diagnosis of pancreatic cysts using magnetic resonance imaging.

OBJECTIVES: To assess the degree of interobserver agreement of MRI in the diagnostic assessment of pancreatic cysts (PCs). METHODS: Magnetic resonance imaging sets of images of 62 patients with PCs (32 with histological confirmation and 30 with clinical diagnosis) were reviewed by 4 experienced radiologists. Features scored included septations, nodules, solid components, pancreatic duct communication, and wall thickening (>2 mm). Radiologists were asked whether they considered the PC mucinous and if the PC was suspicious for malignancy. Furthermore, they had to choose a classifying diagnosis. Intraclass correlation coefficient (ICC) was used to measure agreement within the group. RESULTS: Interobserver agreement for septations and nodules was fair (ICC, 0.36 and 0.23, respectively). Agreement for the presence of solid components was fair (ICC, 0.23), agreement for communication with the pancreatic duct was moderate (ICC, 0.53), and agreement for wall thickening was moderate (ICC, 0.44). There was fair agreement for the discrimination between mucinous and nonmucinous PC (ICC, 0.36). Agreement was fair (ICC, 0.26) for a classifying diagnosis and fair for the presence of malignant features (ICC, 0.33). CONCLUSIONS: Interobserver agreement was poor to moderate for individual PC features, and there was fair agreement for a classifying diagnosis. Magnetic resonance imaging morphology alone did not allow for a reliable discrimination between different types of PC.

Are peritoneal calcifications in long-term peritoneal dialysis related to aortic calcifications and disturbances in mineral metabolism?

BACKGROUND: Peritoneal calcifications are associated with long-term peritoneal dialysis (PD). Case reports have suggested a relation with disturbances in mineral metabolism such as the presence of severe hyperparathyroidism. Our aim was to investigate whether relationships are present between peritoneal calcifications and aortic calcifications or disturbances in mineral metabolism in long-term PD patients. METHODS: We included all long-term PD patients (PD ≥ 4 years) in our centre from 1996 to 2008 who had undergone an abdominal computed tomographic (CT) scan. The scans were reviewed by two experienced radiologists in consensus. The presence or absence of peritoneal calcifications was scored, and a severity scoring system for abdominal aortic calcifications was used: 1 = none, 2 = mild, 3 = moderate, 4 = severe and 5 = very severe. For each patient, laboratory data on plasma calcium corrected for albumin, phosphorus and parathyroid hormone (PTH) levels were retrieved every 6 months up to 5 years prior to the CT scan. Individual mean values over 5 years were calculated. RESULTS: We included 31 patients: 12 patients with peritoneal calcifications and 19 patients without. No difference was found in aortic calcification scores (median scores: 3 versus 3). Also, median (range) calcium, 10.7 (9.6-11.5) versus 10.3 (9.4-11.3) mg/dL; phosphorus, 5.2 (3.4-7.0) versus 4.9 (2.9-6.5) mg/dL; and PTH levels, 271 (101-910) versus 263 (40-1197) pg/mL were not different between patients with and without peritoneal calcifications. CONCLUSIONS: The presence of peritoneal calcifications in long-term PD patients could not be related to the presence of aortic calcifications or disturbances in mineral metabolism. Perhaps, local peritoneal factors play a role in the formation of peritoneal calcifications.

Imaging modalities for focal nodular hyperplasia and hepatocellular adenoma.

BACKGROUND/AIMS: There are several imaging modalities available for the detection of focal liver lesions. Differentiation between focal nodular hyperplasia (FNH) and hepatocellular adenoma (HCA) is important because of the consequences for management. However, differentiation based on imaging alone still shows limitations. METHODS: We reviewed the literature for typical features of FNH and HCA on radiologic and nuclear imaging with emphasis on differentiation of both lesions. RESULTS: Seven articles describe the performance of an imaging modality for the differentiation between FNH and HCA. Limitations of these studies are the small sample size and/or the lack of comparison with the 'gold standard', i.e. histological diagnosis. No studies are available that compare the accuracy of several imaging modalities in the differentiation of FNH and HCA. Conventional ultrasound (US) is not useful in the differentiation because of the non-specific features. On contrast-enhanced US, the arterial filling direction of FNH is centrifugal and centripetal in case of HCA. The parenchymal enhancement of FNH is sustained in the portal venous and delayed phases, but shows rapid washout in case of HCA. Multiphase CT scan can differentiate FNH from HCA when there is a central scar. FNH may have a slightly higher relative enhancement in the arterial phase. On MRI with hepatocyte-specific contrast agents, HCA does not show contrast uptake in the hepatobiliary phase in contrast to FNH. CONCLUSION: We conclude that there is limited evidence of the diagnostic performance of currently used imaging modalities for the differentiation of FNH and HCA. We therefore propose a prospective study (DiFA trial) to determine the accuracy of several radiologic and nuclear imaging studies in differentiating FNH and HCA.

Computed tomographic findings characteristic for encapsulating peritoneal sclerosis: a case-control study.

BACKGROUND: Computed tomography (CT) is often used to confirm the diagnosis of encapsulating peritoneal sclerosis (EPS) but there is no consensus on specific CT abnormalities. To establish CT findings characteristic for EPS, we compared CT findings between EPS patients and long-term peritoneal dialysis (PD) patients without EPS. METHODS: We included as cases all EPS patients in our center from 1996 to 2008 that underwent a CT scan at the time of diagnosis. Controls were all other long-term PD patients (PD duration > or = 4 years) without EPS that had a CT scan for different reasons. The CT scans were blindly and independently reviewed by 3 radiologists: 2 abdominal radiologists with PD knowledge (Observers 1 and 2) and 1 radiologist without PD experience (Observer 3). RESULTS: We included 15 EPS patients and 16 controls. Observer 1 found 6 CT findings that were significantly more often present in EPS than in controls (p < or = 0.05): peritoneal enhancement, thickening, and calcifications; adhesions of bowel loops; signs of obstruction; and fluid loculation/septation. Observer 2 scored almost identically but Observer 3 scored differently. The sensitivity and specificity of a combination of specific CT findings were, respectively, 100% and 94% for Observers 1 and 2, and 79% and 88% for Observer 3. CONCLUSION: CT scans showed characteristic abnormalities that were significantly more often present in EPS patients compared to long-term PD control patients. CT can be used to confirm the diagnosis of EPS when experienced radiologists apply a combination of specific CT findings.