CT colonography: size reduction of submerged colorectal polyps due to electronic cleansing and CT-window settings.

OBJECTIVES: To assess whether electronic cleansing (EC) of tagged residue and different computed tomography (CT) windows influence the size of colorectal polyps in CT colonography (CTC). METHODS: A database of 894 colonoscopy-validated CTC datasets of a low-prevalence cohort was retrospectively reviewed to identify patients with polyps ≥6 mm that were entirely submerged in tagged residue. Ten radiologists independently measured the largest diameter of each polyp, two-dimensionally, before and after EC in colon, bone, and soft-tissue-windows, in randomised order. Differences in size and polyp count before and after EC were calculated for size categories ≥6 mm and ≥10 mm. Statistical testing involved 95% confidence interval, intraclass correlation and mixed-model ANOVA. RESULTS: Thirty-seven patients with 48 polyps were included. Mean polyp size before EC was 9.8 mm in colon, 9.9 mm in bone and 8.2 mm in soft-tissue windows. After EC, the mean polyp size decreased significantly to 9.4 mm in colon, 9.1 mm in bone and 7.1 mm in soft-tissue windows. Compared to unsubtracted colon windows, EC, performed in colon, bone and soft-tissue windows, led to a shift of 6 (12,5%), 10 (20.8%) and 25 (52.1%) polyps ≥6 mm into the next smaller size category, thus affecting patient risk stratification. CONCLUSIONS: EC and narrow CT windows significantly reduce the size of polyps submerged in tagged residue. Polyp measurements should be performed in unsubtracted colon windows. KEY POINTS: • EC significantly reduces the size of polyps submerged in tagged residue. • Abdominal CT-window settings significantly underestimate 2D sizes of submerged polyps. • Size reduction in EC is significantly greater in narrow than wide windows. • Underestimation of polyp size due to EC may lead to inadequate treatment. • Polyp measurements should be performed in unsubtracted images using a colon window.

Differentiation of Intrahepatic Cholangiocellular Carcinoma from Hepatocellular Carcinoma in the Cirrhotic Liver Using Contrast-enhanced MR Imaging.

RATIONALE AND OBJECTIVES: This study aimed to investigate the potential of contrast-enhanced magnetic resonance imaging features to differentiate between mass-forming intrahepatic cholangiocellular carcinoma (ICC) and hepatocellular carcinoma (HCC) in cirrhotic livers. MATERIALS AND METHODS: This study, performed between 2001 and 2013, included 64 baseline magnetic resonance imaging examinations with pathohistologically proven liver cirrhosis, presenting with either ICC (n = 32) or HCC (n = 32) tumors. To distinguish ICC form HCC tumors, 20 qualitative single-lesion descriptors were evaluated by two readers, in consensus, and statistically classified using the chi-square automatic interaction detection (CHAID) methodology. Diagnostic performance was assessed by a receiver operating characteristic analysis. RESULTS: The CHAID algorithm identified three independent categorical lesion descriptors, including (1) liver capsular retraction; (2) progressive or persistent enhancement pattern or wash-out on the T1-weighted delayed phase; and (3) signal intensity appearance on T2-weighted images that could help to reliably differentiate ICC from HCC, which resulted in an AUC of 0.807, and a sensitivity and specificity of 68.8 and 90.6 (95% confidence interval 75.0-98.0), respectively. CONCLUSIONS: The proposed CHAID algorithm provides a simple and robust step-by-step classification tool for a reliable and solid differentiation between ICC and HCC tumors in cirrhotic livers.

Inflammation and Carotid Artery--Risk for Atherosclerosis Study (ICARAS).

BACKGROUND: Compelling evidence suggests that inflammation is fundamentally involved in the pathogenesis of atherosclerosis; however, temporal correlation between inflammation and morphological features of atherosclerosis progression has not been demonstrated unequivocally. METHODS AND RESULTS: We prospectively studied 1268 consecutive patients who were initially asymptomatic with respect to carotid artery disease. Patients underwent serial carotid ultrasound investigations at baseline and after a follow-up interval of a median of 7.5 months (range 6 to 9 months), with measurement of carotid flow velocities and categorization of carotid arteries as 0% to 29%, 30% to 49%, 50% to 69%, 70% to 89%, or 90% to 99% stenosed or occluded. High-sensitivity C-reactive protein (hs-CRP) and serum amyloid A (SAA) were measured at baseline and follow-up. Progression of carotid atherosclerosis was found in 103 (8.1%) of 1268 patients. Hs-CRP and SAA, respectively, at baseline (P=0.004 and P=0.014) and follow-up (P<0.001 and P<0.001) and the change from baseline to follow-up (P<0.001 and P<0.001) were significantly associated with progressive atherosclerosis. Adjusted ORs (95% CI) for atherosclerosis progression with increasing quintiles of baseline hs-CRP were 1.65 (0.71 to 3.84), 1.87 (0.8 to 4.37), 3.32 (1.49 to 7.39), and 3.65 (1.65 to 8.08), and with increasing quintiles of baseline SAA, they were 0.86 (0.38 to 1.92), 0.99 (0.49 to 1.99), 1.72 (0.91 to 3.28), and 2.28 (1.24 to 4.20), respectively, compared with the lowest quintiles. CONCLUSIONS: These findings supply evidence for a close temporal correlation between inflammation and morphological features of rapidly progressive carotid atherosclerosis, which suggests that elevation or increase of the inflammatory biomarkers hs-CRP and SAA identifies the presence of active atherosclerotic disease.

Can Interim 18F-FDG PET or Diffusion-Weighted MRI Predict End-of-Treatment Outcome in FDG-Avid MALT Lymphoma After Rituximab-Based Therapy?: A Preliminary Study in 15 Patients.

PURPOSE: To determine whether interim F-FDG PET or interim diffusion-weighted magnetic resonance imaging (DWI) can predict the end-of-treatment (EOT) outcome after immunotherapy in patients with FDG-avid extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT). MATERIALS AND METHODS: Patients with untreated MALT lymphoma prospectively underwent whole-body F-FDG PET/CT and DWI before treatment (baseline), and after three cycles (interim) of rituximab-based immunotherapy. Maximum and mean standardized uptake values (SUVmax, SUVmean), and minimum and mean apparent diffusion coefficients (ADCmin, ADCmean), were measured for up to three target lesions per patient. Rates of change between baseline and interim examinations (ΔSUVmax, ΔSUVmean, ΔADCmin, and ΔADCmean) were compared, using ANOVAs, between the four end-of-treatment (EOT, after six cycles of immunotherapy) outcomes: complete remission (CR), partial remission (PR), stable disease (SD), or progressive disease (PD). RESULTS: Fifteen patients with 25 lesions were included. Lesion-based post hoc tests showed significant differences between CR and PR for ΔSUVmax (P < 0.001), ΔSUVmean (P < 0.001), and ΔADCmin (P = 0.044), and between CR and SD for ΔSUVmax (P < 0.001), ΔSUVmean (P < 0.001), ΔADCmin (P = 0.021), and ΔADCmean (P = 0.022). No lesion showed PD at EOT. CONCLUSIONS: Both quantitative interim F-FDG PET and interim DWI may possibly be useful to predict complete remission at end-of-treatment in MALT lymphoma patients after immunotherapy.

Does Delayed-Time-Point Imaging Improve 18F-FDG-PET in Patients With MALT Lymphoma?: Observations in a Series of 13 Patients.

PURPOSE: To determine whether in patients with extranodal marginal zone B-cell lymphoma of the mucosa-associated lymphoid tissue lymphoma (MALT), delayed-time-point 2-F-fluoro-2-deoxy-d-glucose-positron emission tomography (F-FDG-PET) performs better than standard-time-point F-FDG-PET. MATERIALS AND METHODS: Patients with untreated histologically verified MALT lymphoma, who were undergoing pretherapeutic F-FDG-PET/computed tomography (CT) and consecutive F-FDG-PET/magnetic resonance imaging (MRI), using a single F-FDG injection, in the course of a larger-scale prospective trial, were included. Region-based sensitivity and specificity, and patient-based sensitivity of the respective F-FDG-PET scans at time points 1 (45-60 minutes after tracer injection, TP1) and 2 (100-150 minutes after tracer injection, TP2), relative to the reference standard, were calculated. Lesion-to-liver and lesion-to-blood SUVmax (maximum standardized uptake values) ratios were also assessed. RESULTS: F-FDG-PET at TP1 was true positive in 15 o f 23 involved regions, and F-FDG-PET at TP2 was true-positive in 20 of 23 involved regions; no false-positive regions were noted. Accordingly, region-based sensitivities and specificities were 65.2% (confidence interval [CI], 45.73%-84.67%) and 100% (CI, 100%-100%) for F-FDG-PET at TP1; and 87.0% (CI, 73.26%-100%) and 100% (CI, 100%-100%) for F-FDG-PET at TP2, respectively. FDG-PET at TP1 detected lymphoma in at least one nodal or extranodal region in 7 of 13 patients, and F-FDG-PET at TP2 in 10 of 13 patients; accordingly, patient-based sensitivity was 53.8% (CI, 26.7%-80.9%) for F-FDG-PET at TP1, and 76.9% (CI, 54.0%-99.8%) for F-FDG-PET at TP2. Lesion-to-liver and lesion-to-blood maximum standardized uptake value ratios were significantly lower at TP1 (ratios, 1.05 ± 0.40 and 1.52 ± 0.62) than at TP2 (ratios, 1.67 ± 0.74 and 2.56 ± 1.10; P = 0.003 and P = 0.001). CONCLUSIONS: Delayed-time-point imaging may improve F-FDG-PET in MALT lymphoma.