Coronary computed tomography angiography (CCTA): effect of bolus-tracking ROI positioning on image quality.

OBJECTIVES: The aim of the study was to evaluate the effect of bolus-tracking ROI positioning on coronary computed tomography angiography (CCTA) image quality. METHODS: In this retrospective monocentric study, all patients had undergone CCTA by step-and-shoot mode to rule out coronary artery disease within a cohort at intermediate risk. Two groups were formed, depending on ROI positioning (left atrium (LA) or ascending aorta (AA)). Each group contained 96 patients. To select pairs of patients, propensity score matching was used. Image quality with regard to coronary arteries as well as pulmonary arteries was evaluated using quantitative and qualitative scores. RESULTS: In terms of the coronary arteries, there was no significant difference between both groups using quantitative (SNR AA 14.92 vs. 15.46; p = 0.619 | SNR LM 19.80 vs. 20.30; p = 0.661 | SNR RCA 24.34 vs. 24.30; p = 0.767) or qualitative scores (4.25 vs. 4.29; p = 0.672), respectively. With regard to pulmonary arteries, we found significantly higher quantitative (SNR RPA 8.70 vs. 5.89; p < 0.001 | SNR LPA 9.06 vs. 6.25; p < 0.001) and qualitative scores (3.97 vs. 2.24; p < 0.001) for ROI positioning in the LA than for ROI positioning in the AA. CONCLUSIONS: ROI positioning in the LA or the AA results in comparable image quality of CT coronary arteriography, while positioning in the LA leads to significantly higher image quality of the pulmonary arteries. These results support ROI positioning in the LA, which also facilitates triple-rule-out CT scanning. KEY POINTS: • ROI positioning in the left atrium or the ascending aorta leads to comparable image quality of the coronary arteries. • ROI positioning in the left atrium results in significantly higher image quality of the pulmonary arteries. • ROI positioning in the left atrium is feasible to perform triple-rule-out CTA.

Diffusion-weighted MRI for initial staging in Hodgkin`s lymphoma: comparison with FDG PET.

PURPOSE: To evaluate the use of diffusion-weighted MRI (DWI) for initial staging of Hodgkin`s lymphoma and compare it to FDG PET. METHODS: Forty-one patients with Hodgkin`s lymphoma (14 f, 27 m, median age 39 y) were included in this retrospective study. All patients underwent FDG PET/MR for initial staging, including DWI. The Lugano classification was used to describe disease extent. A combination of follow-up imaging and histopathology served as the reference standard. Method agreement was assessed using weighted kappa (κ). The accuracy of the imaging methods was evaluated using ROC curve analysis. RESULTS: Regarding the Lugano stage, DWI and FDG PET had identical results in 34/41 cases (κ = 0.77). Sensitivity and specificity for nodal involvement was 89.9% and 93.8% for DWI, and 93.8% and 86.9% for FDG PET, respectively. In regard to extranodal involvement, sensitivity and specificity were 88.5% and 99.3% for DWI and 92.3% and 92.7% for FDG PET. The accuracy of both methods for nodal (p = 0.06) and extranodal involvement (p = 0.66) did not differ significantly. CONCLUSION: Despite high sensitivity and specificity, DWI in free breathing cannot be currently recommended as an alternative to FDG PET in initial staging of Hodgkin`s lymphoma due to substantial differences in regard to therapy-determining Lugano Stage.

Iminium Catalysis inside a Self-Assembled Supramolecular Capsule: Scope and Mechanistic Studies.

Although iminium catalysis has become an important tool in organic chemistry, its combination with supramolecular host systems has remained largely unexplored. We report the detailed investigations into the first example of iminium catalysis inside a supramolecular host. In the case of 1,4-reductions of α,ß-unsaturated aldehydes, catalytic amounts of host are able to increase the enantiomeric excess of the products formed. Several control experiments were performed and provided strong evidence that the modulation of enantiomeric excess of the reaction product indeed stems from a reaction on the inside of the capsule. The origin of the increased enantioselectivity in the capsule was investigated. Furthermore, the substrate and nucleophile scope were studied. Kinetic investigations as well as the kinetic isotope effect measured confirmed that the hydride delivery to the substrate is the rate-determining step inside the capsule. The exploration of benzothiazolidines as alternative hydride sources revealed an unexpected substitution effect of the hydride source itself. The results presented confirm that the noncovalent combination of supramolecular hosts with iminium catalysis is opening up new exciting possibilities to increase enantioselectivity in challenging reactions.

Iminium Catalysis inside a Self-Assembled Supramolecular Capsule: Modulation of Enantiomeric Excess.

The noncovalent combination of a supramolecular host with iminium organocatalysis is described. Due to cation-π interactions the reactive iminium species is held inside the host and reacts in this confined environment. The products formed differ up to 92 % ee from the control experiments without added host. A model rationalizing the observed difference is presented.

Exploring Catalysis inside Self-assembled Supramolecular Containers.

Our group is interested in applying supramolecular host systems as catalysts for challenging transformations. Although a variety of supramolecular containers has been described in literature, their use as reaction chambers is still underexplored. We herein describe our first steps in this exciting interdisciplinary field of research.

Multiparametric Prostate Magnetic Resonance Imaging at 3 T: Failure of Magnetic Resonance Spectroscopy to Provide Added Value.

PURPOSE: To assess the effect of proton magnetic resonance spectroscopy imaging (MRSI) on the accuracy of multiparametric magnetic resonance imaging (mpMRI) at 3 T for prostate cancer detection. MATERIALS AND METHODS: Thirty-four patients with prostate cancer were included in this retrospective study. All patients underwent preoperative mpMRI on a 3-T scanner before radical prostatectomy. Magnetic resonance imaging evaluation was based on the prostate imaging-reporting and data system classification system. The accuracy of mpMRI with and without MRSI was determined using receiver operating characteristic analysis, with histology as the reference standard. RESULTS: Multiparametric MRI including MRSI had a sensitivity of 57.0% and a specificity of 89.2% for sextant-based cancer detection. Multiparametric MRI without MRSI had a sensitivity of 58.1% and a specificity of 87.4%. There was no significant difference regarding the accuracy of mpMRI with and without MRSI (P = 0.48). CONCLUSION: The addition of MRSI does not improve the accuracy of 3 T mpMRI for sextant localization of prostate cancer.

Evaluation of racing performance after colic surgery in Thoroughbreds: 85 cases (1996-2010).

OBJECTIVE: To determine racing performance after surgery for colic in Thoroughbreds. DESIGN: Retrospective cohort study. ANIMALS: 85 racing Thoroughbreds that survived to discharge following colic surgery and 170 race-matched reference horses. PROCEDURES: Earnings, starts, and earnings per start were compared between horses that underwent surgery and reference horses, the proportions of horses that returned to racing were analyzed, and career longevity was determined. RESULTS: Among 85 racing Thoroughbreds that underwent colic surgery, 31 (36%) had primarily small intestinal lesions, of which 11 underwent resection; 54 (64%) had large intestinal lesions, of which 2 underwent resection. Fifty-nine of 85 (69%) horses that underwent colic surgery returned to racing after a 6-month recovery period versus 125 of 170 (73%) reference horses (OR, 0.81). In the 36-month postoperative period, reference horses earned a mean of $7,866 more, had a mean of 0.26 more starts, and had mean earnings per start of $29 more than horses that underwent surgery. Horses that underwent surgery did not have different career lengths than reference horses. CONCLUSIONS AND CLINICAL RELEVANCE: Horses that underwent colic surgery did not have a significant reduction in measures of performance or career length, compared with a reference cohort.

Transarterial Chemoembolization of Child-A hepatocellular carcinoma: drug-eluting bead TACE (DEB TACE) vs. TACE with cisplatin/lipiodol (cTACE).

BACKGROUND: This study is an outcome evaluation of the Drug-Eluting-Bead-Chemoembolization (DEB TACE) compared to conventional TACE (cTACE) with Cisplation and Lipiodol in patients with hepatocellular carcinoma (HCC) and Child-Pugh A Cirrhosis. MATERIAL/METHODS: A comparison of interventional therapy with either cTACE or DEB-TACE of 22 patients each with unresectable HCC and Child-Pugh A Cirrhosis was carried out. A comparison of therapy-associated complications, tumour response rates and mean survival was performed. Tumour response was evaluated in accordance with the European Association for the Study of the Liver (EASL) response criteria by two radiologists in consensus reading. RESULTS: The choice of TACE procedure (DEB TACE/cTACE) had no significant impact on therapy-associated complications. Objective Response (OR, complete response + partial response) for DEB-TACE was 22.7%; a further 68.2% was stable disease (SD). The respective response rates for the cTACE were OR 22.7 and SD 31.8%. Thus disease control was not significantly increased for DEB TACE (p=0.066). After DEB-TACE mean survival was significantly prolonged with 651 ± 76 days vs. 414 ± 43 days for cTACE (p=0.01). CONCLUSIONS: Associated with a similar safety profile and an at least comparable tumour response, the DEB-TACE is a method of treatment for HCC that has the potential to improve mean survival compared to cTACE with Cisplatin/Lipiodol.