Assessment of hepatic steatosis in patients undergoing liver resection: comparison of US, CT, T1-weighted dual-echo MR imaging, and point-resolved 1H MR spectroscopy.

PURPOSE: To compare the diagnostic performance of ultrasonography (US), computed tomography (CT), T1-weighted dual-echo magnetic resonance (MR) imaging, and point-resolved proton (hydrogen 1[(1)H]) MR spectroscopy in the assessment of hepatic steatosis in patients undergoing liver resection. MATERIALS AND METHODS: This prospective study was approved by the institutional review board, and patients gave written informed consent. US, CT, T1-weighted MR imaging, and (1)H MR spectroscopy were performed preoperatively in 46 patients. Imaging results were correlated (Spearman correlation coefficient) with histopathologic analysis of results of intraoperative liver biopsies. To assess differences between groups, one-way analysis of variance was used. Sensitivity and specificity were calculated for each imaging modality by using receiver operating characteristic curve analysis, with a histopathologic cut-off value of 5% macrovesicular steatosis. Differences in sensitivity and specificity were assessed by means of McNemar analysis. RESULTS: At histopathologic examination, 23 patients had no (0%-5%) macrovesicular steatosis, 11 had mild (5%-33%), nine had moderate (33%-66%), and three had severe (>66%). MR imaging and (1)H MR spectroscopic measurements of hepatic fat had stronger correlation with histopathologic steatosis assessment (r = 0.85, P < .001 and r = 0.86, P < .001, respectively) than did US (r = 0.66, P < .001) and CT (r = -0.55, P < .001). Only T1-weighted MR imaging and (1)H MR spectroscopy showed differences across steatosis grades: none versus mild (P = .001 for both), mild versus moderate (P < .001 for both), and moderate versus severe (P = .04 and .01, respectively). Sensitivity of US, CT, T1-weighted MR imaging, and (1)H MR spectroscopy was 65% (13 of 20), 74% (17 of 23), 90% (19 of 21), and 91% (21 of 23), respectively, and specificity was 77% (17 of 23), 70% (14 of 20), 91% (20 of 22), and 87% (20 of 23), respectively. CONCLUSION: In contrast to US and CT, T1-weighted MR imaging and (1)H MR spectroscopy strongly correlate with histopathologic steatosis assessment and are able to demonstrate differences across steatosis grades. T1-weighted dual-echo MR imaging and (1)H MR spectroscopy had the best diagnostic accuracy in depicting hepatic steatosis.

Diagnostic strategies for pre-treatment staging of patients with oesophageal cancer.

BACKGROUND/AIMS: Current guidelines for staging oesophageal cancer recommend a series of preoperative investigations. There is no consensus on the recommended order for these investigations or whether all investigations are necessary in all patients. Our aim was to determine an efficient strategy for pre-treatment staging of patients with oesophageal cancer. METHODS: We retrospectively compared 15 staging strategies, based on all possible orders of all possible subsets of three staging modalities (computed tomography, endoscopic ultrasonography and external ultrasonography of the neck). We assumed that if distant metastases or local irresectability were found and confirmed, no further investigations would be performed. Main outcome was the minimal number of investigations needed to detect all patients with incurable disease. RESULTS: Using all three investigations in all 412 patients would lead to performance of 1,236 investigations. Both strategies starting with computed tomography or endoscopic ultrasonography and ending with external ultrasonography were most efficient, using a total of 1,112 investigations. CONCLUSION: The use of a conditional staging strategy with a specific order of imaging can reduce the number of tests necessary to identify incurable patients with oesophageal cancer by 10%. In our opinion, this is not enough to recommend implementation of a logistically more complex diagnostic system.