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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.

Background: Chemoradiotherapy is increasingly applied in patients with oesophageal cancer. The aim of the present study was to determine whether 3D-CT volumetry is able to differentiate between responding and non-responding oesophageal tumours early in the course of neoadjuvant chemoradiotherapy., Patients and Methods: Serial CT before and after two weeks of neoadjuvant chemoradiotherapy was performed in the multimodality treatment arm of a randomised trial including patients with oesophageal carcinoma. CT response was measured with the change in tumour volume between baseline and after 14 days of neoadjuvant therapy. Receiver Operating Characteristic (ROC) analysis was used to evaluate the ability of 3D-CT as an early imaging marker of response., Results: CT response analysis was performed in 39 patients, of whom 26 patients were histopathological responders. Median tumour volume increased between baseline and after 14 days of chemoradiotherapy in histopathological responders as well as in non-responders, though changes were not statistically significant. The area under the ROC curve was 0.71., Conclusion: Tumour volume changes after 14 days of neoadjuvant chemoradiotherapy as measured by 3D-CT were not associated with histopathological tumour response. CT volumetry should not be used for early response assessment in patients with potentially curable oesophageal cancer treated with neoadjuvant chemoradiotherapy., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

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.

Background and Objective: Survival is often poor after resection of pancreatic tumors. We correlated the pre-operative CTs with survival to find criteria that have prognostic value. To establish the prognostic value of CT in patients with potentially resectable pancreatic head carcinoma., Methods: In 71 consecutive patients with potentially resectable pancreatic head carcinoma, prognostic factors on CT were scored, for example, tumor size, peripancreatic infiltration, grades of vascular encasement, and local irresectability. All patients underwent surgical exploration. CT findings were compared with results of surgery and histopathology. Prognostic factors for resected and unresected tumors were analyzed using single and multivariate analysis., Results: Forty-one of 71 tumors were resected (24 radical). The sensitivity, specificity, and positive predictive value of CT for surgical irresectability were 0.67, 0.63, and 0.57, respectively. For a non-radical resection, these were 0.62, 0.75, and 0.83, respectively. The median survival was 21 months for resectable tumors and 9.7 months for unresectable tumors. For resected tumors, a tumor diameter of > 3 cm (relative hazard 3.8) and CT signs of local unresectability showed a poor survival. The median survival of resected tumors <2 cm was nearly 30 months., Conclusion: CT signs of local irresectability and a tumor diameter of >3 cm predict a poor survival after resection.

The purpose of the study was to evaluate CT criteria for venous invasion in patients with potentially resectable carcinoma of the pancreatic head, with surgical and histopathological correlation. In 113 patients evaluated with spiral CT for suspected pancreatic head carcinoma, several CT criteria for venous invasion were scored prospectively for the portal vein (PV) and the superior mesenteric vein (SMV): length of tumour contact with PV/SMV (0 mm, < 5 mm, > 5 mm); circumferential involvement of the vein (0 degree, 0-90 degrees, 90-180 degrees, > 180 degrees); degree of stenosis; irregularity of the vessel margin; and tumour convexity towards vessel. 65 patients underwent surgery. Pancreatic head carcinoma was proven and pathology of the vascular margin was obtained in 50 of these patients. CT findings for single and combined criteria were correlated with pathology in these 50 patients, 30 of whom showed venous ingrowth. Invasion was found in all cases with SMV narrowing (n = 7), PV contour involvement > 90 degrees (n = 6), PV narrowing (n = 5) and PV wall irregularity (n = 3). The vascular ingrowth rate was 88% (15/17) for tumour concavity towards the PV or SMV. Poor predictors of ingrowth were length of tumour contact with PV > 5 mm (78% ingrowth, 14/18) and contour involvement of the SMV > 90 degrees (83% ingrowth, 10/12). Absence of vascular ingrowth could not be predicted in 100%. In conclusion, CT criteria can predict a high risk of invasion in potentially resectable tumours. Narrowing of the SMV and the PV seems the most reliable criterion, as well as circumferential involvement of the PV > 90 degrees. The best combination of criteria was tumour concavity with circumferential involvement > 90 degrees (sensitivity 60% and positive predictive value 90%).

Purpose: To investigate whether coronal multiplanar reconstruction (MPR) images of the petrosal bone from axial spiral computed tomographic (CT) data obtained with 0.5-mm collimation can replace direct coronal sequential CT scans obtained with 0.5- or 1.0-mm collimation., Materials and Methods: The differences in diagnostic quality between thin-section coronal sequential CT scans of 24 petrosal bones in 12 patients and matched MPR images were assessed by five observers. The matched MPR images were calculated with both trilinear and tricubic interpolation. Image resolution was determined by measuring the three-dimensional point spread function., Results: All observers preferred tricubically interpolated MPR images over trilinearly interpolated images. Subjective differences in image quality between direct coronal scans and matched tricubically interpolated MPR images were small. Only the direct coronal scans with the highest image quality (0.5-mm collimation, 465 mAs) were judged to be slightly better than the matched MPR images. With regard to direct coronal scans obtained at 245 mAs and/or 1.0-mm collimation, either there was no preference or the MPR images were preferred., Conclusion: Coronal MPR images from axial spiral CT obtained with 0.5-mm collimation can replace direct coronal sequential CT scans.

Background: Pancreatic cancer is often locally invasive. Preoperative staging attempts to identify patients suitable for resection, in order to minimize unnecessary operations. The aim of this study was to assess the improved imaging provided by spiral computed tomography (CT) in the preoperative staging of potentially resectable pancreatic head carcinoma., Methods: In 56 consecutive patients with pancreatic head carcinoma spiral CT findings were correlated prospectively with operative and histopathological findings. Criteria for irresectability at CT were infiltration of the peripancreatic fat and vascular ingrowth grade D, on a scale from A to F., Results: At operation 27 (48 per cent) of 56 tumours were irresectable. Small metastases were found in seven patients (12 per cent). Ingrowth (adherence) to the portal or mesenteric vein was present in 19 patients (34 per cent). The sensitivity and specificity of CT for irresectability were 78 and 76 per cent respectively. Resection rates with a vascular margin free of tumour were 100 per cent for grade A, 63 per cent for grade B, 44 per cent for grade C, 15 per cent for grade D and 0 per cent for grade E, with a predictive value for ingrowth of 88 per cent for grades D or higher. The resectability rate was 11 per cent (one of nine) when infiltration of the anterior peripancreatic fat was present and 67 per cent when infiltration was absent (P < 0.01)., Conclusion: Spiral CT with thin slices seems to improve detection of distant metastases and vascular ingrowth in patients with pancreatic head carcinoma.