Contrast-enhanced ultrasonography (CEUS) vs. MRI of the small bowel in the evaluation of Crohn's disease activity.

PURPOSE: The presence of disease activity in Crohn's disease (CD) is one of the main parameters used to establish whether optimal therapy should be drug therapy or surgery. However, a major problem in monitoring CD is the common mismatch between the patient's symptoms and imaging objective signs of disease activity. Bowel ultrasonography (US) has emerged as a low-cost, noninvasive technique in the diagnosis and follow-up of patients with CD. Accordingly, the use of contrast-enhanced US (CEUS) has made possible an evaluation of the vascular enhancement pattern, similar to the use of magnetic resonance imaging (MRI). The aim of our study was to evaluate the role of CEUS in comparison with small-bowel MRI for assessing Crohn's disease activity. MATERIALS AND METHODS: We prospectively enrolled 30 consecutive patients with known CD. Clinical and laboratory data were compared with imaging findings obtained from MRI and CEUS of the small bowel. MRI was performed with a 1.5-T system using phased-array coils and biphasic orally administered contrast agent prior to and after gadolinium chelate administration. We performed US with a 7.5-MHz linear-array probe and a second-generation contrast agent. The parameters analysed in both techniques were the following: lesion length, wall thickness, layered wall appearance, comb sign, fibroadipose proliferation, presence of enlarged lymph nodes and stenosis. We classified parietal enhancement curves into two types in relation to the contrast pattern obtained with the time-intensity curves at MRI and CEUS: (1) quick washin, quick washout, (2) slow washin, plateau with a slow washout. RESULTS: Comparison between Crohn's disease activity index (CDAI) and MRI showed a low correlation, with an rho=0.398; correlation between CDAI-laboratory data and CEUS activity was low, with rho=0.354; correlation between MRI activity and CEUS activity was good, with rho = 0.791; high correlation was found between CEUS and MRI of the small bowel when assessing wall-thickness, lymph nodes and comb sign; good correlation was fund when assessing layered wall appearance, disease extension and fibroadipose proliferation. At MRI, time-intensity curves for 12/30 patients were active, compared with for 14/30 patients at CEUS; therefore there was a poor correlation between curve on CEUS and curve on MRI (r=0.167; p=0.36). CONCLUSIONS: The use of CEUS can be recommended if there is a discrepancy between MRI and clinical/laboratory parameters. MRI of the small bowel remains the most accurate method for evaluating disease activity.

Comparison between different kernel reformatting filters in 3D quantitative analysis of MDCT coronary angiography.

PURPOSE: Coronary angiography with multidetector-row computed tomography (MDCT-CA) allows quantification of coronary artery stenosis with a high level of accuracy; however, a better estimation of stenosis can be achieved by using appropriate reformatting filters, especially in stents and calcified segments. Quantitative computed tomography angiography (QCTA) is intended to overcome the limitations of the visual score. The aim of this study was to evaluate the accuracy of QCTA with different filters in comparison with quantitative coronary angiography (QCA) and visual score. MATERIALS AND METHODS: Two blinded operators visually scored 17 consecutive patients referred for MDCT-CA with a per-segment analysis. The degree of stenosis was classified as 0-20%, 20-50% (wall irregularities), 50-70% (significant disease) and 70-100% (vessel occlusion). Each segment was then analysed using the electronic callipers of the QCTA system with 15 different filters. No contour editing was performed. Data were compared with QCA and conventional coronary angiography (CCA). Comparison between QCTA, visual score and QCA were performed using Spearman's rank correlation. RESULTS: Of 25 segments analysed (mean 1.4 diseased segment per patient), 375 measurements were considered. Good correlation was found between the visual score and QCA [Pearson correlation coefficient (rho=0.852; p<0.0001)] and between QCA and CCA (rho=0.804; p<0.0001). Moderate correlation was found between QCA and QCTA only using two filters (rho=0.444; p<0.0001 for YA filter and rho=0.450; p<0.0001 for YB filter). CONCLUSIONS: Overall QCTA accuracy is low if contour editing is not applied, especially in calcified vessels. Certain filters can help to better estimate the exact percentage of stenosis.

MDCT coronary angiography vs 2D echocardiography for the assessment of left ventricle functional parameters.

PURPOSE: This study was done to compare the parameters of left ventricular (LV) function obtained by multidetector computed tomography coronary angiography (MDCT-CA) using 64-slice equipment with those obtained using twodimensional echocardiography (2D-SE) considered as reference standard. MATERIALS AND METHODS: Between April 2008 and September 2009, 116 consecutive patients were studied with both techniques. We analysed the parameters commonly sampled in echocardiography and related them with those retrieved with MDCT-CA: septal thickness, posterior wall thickness, diameter of ascending aorta, diameter and volumes in end-systolic and end-diastolic phase, ejection fraction, stroke volume, cardiac output and heart mass. RESULTS: Good correlation was found measuring septal thickness (r=0.470; p=0.001), and diameters of the ascending aorta. Correlation between systolic and diastolic diameters obtained with the two techniques was good. Poor correlation was attained measuring thickness of the posterior wall (r=0.243; p=0.104). MDCT-CA consistently overestimated the average volumes; diastolic and systolic volumes showed significant correlation (r=0.0456; p= 0.002; r=0.640; p<0.001). Ejection fraction agreement showed a significant correlation (r=0.626; p<0.001). CONCLUSIONS: MDCT-CA provides parameters of cardiac function comparable to those found in echocardiography. MDCT-CA although used primarily for coronary noninvasive imaging can provide additional information on ventricular function useful to the diagnostic workup of cardiac patients.