BACKGROUND:The diagnostic performance of multidetector row CT to detect coronary artery stenosis has been evaluated in numerous single-center studies, with only limited data from large cohorts with low-to-intermediate likelihood of coronary disease and in multicenter trials. The Multicenter Evaluation of Coronary Dual-Source CT Angiography in Patients with Intermediate Risk of Coronary Artery Stenoses (MEDIC) trial determines the accuracy of dual-source CT (DSCT) to identify persons with at least 1 coronary artery stenosis among patients with low-to-intermediate pretest likelihood of disease.METHODS:The MEDIC trial was designed as a prospective, multicenter, international trial to evaluate the diagnostic performance of DSCT for the detection of coronary artery stenosis compared with invasive coronary angiography. The study includes 8 sites in Germany, India, Mexico, the United States, and Denmark. The study population comprises patients referred for a diagnostic coronary angiogram because of suspected coronary artery disease with an intermediate pretest likelihood as determined by sex, age, and symptoms. All evaluations are performed by blinded core laboratory readers.RESULTS:The primary outcome of the MEDIC trial is the accuracy of DSCT to identify the presence of coronary artery stenoses with a luminal diameter narrowing of 50% or more on a per-vessel basis. Secondary outcome parameters include per-patient and per-segment diagnostic accuracy for 50% stenoses and accuracy to identify stenoses of 70% or more. Furthermore, secondary outcome parameters include the influence of heart rate, Agatston score, body weight, body mass index, image quality, and diagnostic confidence on the accuracy to detect coronary artery stenoses >50% on a per-vessel basis.CONCLUSION:The results of the MEDIC trial will assess the clinical utility of coronary CT angiography in the evaluation of patients with intermediate pretest likelihood of coronary artery disease.

Introduction: The potential of sonography in the examination of lung tissue is extremely limited by the air-filled alveoles of the lung. Only in special circumstances like pleural adhesion lesions, atelectasis or pneumonia can lung tissue be visualized by B-mode sonography. Real-time elastography was primarily applied to detect and visualize pulmonary lesions.Methods and Patients: 8 patients with a total of 18 histologically proven metastases of the lung were included. All pulmonary lesions were detected by computed tomography. Sonographic examination was performed with a 7.5MHz linear transducer (Acuson Antares premium edition, Siemens, Erlangen, Germany), including B-mode and real-time elastography (RTE). The mean distance between pleura and the lesions ranged from 0 to 2.5 cm. Two lesions were located in the upper right lobe, eleven lesions in the lower right and five in the lower left lobe.Results: RTE was able to detect and visualize all 18 pulmonary lesions in contrast to B-mode. The size and distance of the lesions from the pleura correlated with the CT findings.Conclusion: In contrast to B-mode sonography, RTE is able to detect and visualize peripheral, non-pleural adherent pulmonary lesions.

True automated detection of coronary artery stenoses might be useful whenever expert evaluation is not available, or as a “second reader” to enhance diagnostic confidence. We evaluated the accuracy of a PC-based stenosis detection tool alone and combined with expert interpretation.

BACKGROUND: In transcatheter aortic valve implantation (TAVI), optimal selection of fluoroscopic projections that permit orthogonal visualization of the aortic valve plane is important but may be difficult to achieve.OBJECTIVE: We developed and validated a simple method to predict suitable fluoroscopic projections on the basis of cardiac CT datasets.METHODS: In 75 consecutive patients that underwent TAVI, angulations in which a 35-mm thick maximum intensity projection would render all aortic valve calcium into I plane were determined by manual interaction with contrast-enhanced dual-source CT datasets. TAVI operators used the predicted angulation for the first aortic angiogram and performed additional aortic angiograms if no satisfactory view of the aortic valve plane was obtained. Predicted angulations were compared with the angulation used for valve implantation. Radiation exposure and contrast use was compared between patients with accurate prediction of fluoroscopic angulations by CT and patients in whom CT failed to predict a suitable view.RESULTS: The mean difference between the predicted angulation according to CT and the angulation used for implantation was 3 +/- 6 degrees. CT predicted a suitable angulation (<5-degree deviation) in 63 of 75 cases (84%). The mean number of aortic angiograms acquired in patients with correct prediction (1.02 +/- 0.1) was significantly lower than in patients with incorrect prediction of the implantation angle by CT (3.0 +/- 1.7; P < 0.001). Contrast agent required for the entire TAVI procedure was lower in patients with correct prediction (72 +/- 36 mL vs 106 +/- 39 mL; P = 0.001).CONCLUSION: CT permits prediction of suitable angulations for TAVI in most cases. (C) 2012 Society of Cardiovascular Computed Tomography. All rights reserved.

Background: Aim of this study was to compare DNA double-strand breaks (DSBs) in blood lymphocytes of patients undergoing high-pitch helical, low-pitch helical and sequential coronary CT angiography.Methods and results: 66 patients were examined with various scan protocols and modes (low-pitch helical scan: 100-120 kV, 320-438 mAs/rot, pitch 0.18-0.39, with or without ECG-pulsing, n = 35; prospectively ECG-triggered high-pitch helical scan: 100-120 kV, 320-456 mAs/rotation, pitch 3.2-3.4, n = 19; prospectively ECG-triggered sequential scan: 100-120 kV, 150-300 mAs or 320-370 mAs/rotation, n = 12) either using a 64-slice or 128-slice dual-source CT or a 128-slice single source CT scanner. Blood samples were obtained before and 30 min after CT and DSBs were analyzed in isolated lymphocytes using gamma-H2AX immunofluorescence microscopy.A significant increase of DSBs was measurable 30 min after CTA (range 0.01-0.71/cell). CT induced DSBs showed a significant correlation with the estimated effective dose (rho = 0.90, p < 0.00001). Both prospectively ECG-triggered sequential (0.10 DSBs/cell, 176 mGy cm, p < 0.00001) and high-pitch helical scan protocols (0.03 DSBs/cell, 109 mGy cm, p < 0.00001) led to a significant reduction of median DLP and DSB levels compared to low-pitch helical scans (0.34 DSBs/cell, 828 mGy cm). A reduction of the tube voltage resulted in significantly lower whereas additional calcium scoring resulted in elevated DLP and DNA damages (p < 0.05 each).Conclusion: In coronary CTA, data acquisition protocols have a significant influence on the X-ray induced DSB levels. Using gamma-H2AX immunofluorescence microscopy different scan modes in different CT generations can be compared concerning their biological impact. (C) 2011 Elsevier Ireland Ltd. All rights reserved.

The purpose of this study was to evaluate DNA double-strand breaks (DSBs) in blood lymphocytes of patients undergoing positron emission tomography (PET)/CT using γ-H2AX immunofluorescence microscopy and to differentiate between 18F-fluorodeoxyglucose (FDG) and CT-induced DNA lesions.

Die rasante Entwicklung in der CT und MRT hat die Herzbildgebung wieder in den Fokus der Radiologie gebracht. Die CT wird bereits auf breiter Basis für die nichtinvasive Diagnostik der Koronargefäße, insbesondere zum Ausschluss einer koronaren Herzerkrankung eingesetzt. Die Arbeitsgemeinschaft Herz- und Gefäßdiagnostik in der Deutschen Röntgengesellschaft hat für die Computertomographie und die Magnetresonanzverfahren ein mehrstufiges Qualifizierungskonzept beruhend auf zertifizierten CME Fortbildungsaktivitäten und klinisch-praktischer Erfahrung entwickelt.

Transcatheter Aortic Valve Implantation (TAVI) is an alternative to surgical valve replacement in high risk patients. Angiography of the aortic root, aorta and iliac arteries is required to select suitable candidates, but contrast agents can be harmful due to impaired renal function. We evaluated ECG-triggered high-pitch spiral dual source Computed Tomography (CT) with minimized volume of contrast agent to assess aortic root anatomy and vascular access.

Im Rahmen einer Phantomstudie sollte untersucht werden, ob ein neues System zur digitalen Vollfeldmammographie, das mit einem Doppelschicht-Selen-Detektor ausgestattet ist, im Vergleich zu 2 anderen, bereits etablierten Mammographiesystemen eine bessere oder zumindest gleichwertige Detektionsrate für simulierte mammographische Läsionen erzielt.

OBJECTIVES We sought to evaluate the diagnostic accuracy of a new prospectively electrocardiogram (ECG)-triggered high-pitch scan mode for coronary computed tomography angiography (CTA), which allows an effective dose of less than 1 mSv.BACKGROUND Coronary CTA provides increasingly reliable image quality, but the associated radiation exposure can be high.METHODS Seventy-five patients with suspected coronary artery disease and in sinus rhythm were screened for participation. After exclusion of 25 patients for body weight >100 kg or failure to lower heart rate to <60 beats/min, 50 patients were studied by prospectively ECG-triggered high-pitch spiral computed tomography (CT). Coronary CTA was performed using a dual-source CT system with 2 X 128 X 0.6-mm collimation, 0.28-s rotation time, a pitch of 3.4, 100-kVp tube voltage, and current of 320 mA. Data acquisition was prospectively triggered at 60% of the R-R interval and completed within 1 cardiac cycle. Diagnostic accuracy for detection of coronary artery stenoses >= 50% diameter stenosis was determined by comparison to invasive coronary angiography. Per-patient diagnostic performance was the primary form of analysis.RESULTS In all 50 patients (34 males, 59 +/- 12 years of age), imaging was successful. For the detection of 16 patients with at least 1 coronary artery stenosis, CT demonstrated a sensitivity of 100% (95% confidence interval [CI]: 79% to 100%) and specificity of 82% (95% CI: 65% to 93%). The positive predictive value was 72% (95% CI: 49% to 89%) and the negative predictive value was 100% (95% CI: 87% to 100%). Sensitivity was 100% (95% CI: 88% to 100%) and specificity was 94% (95% CI: 89% to 97%) on a per-vessel basis. Per-segment sensitivity was 92% (95% CI: 80% to 97%), and specificity was 98% (95% CI: 96% to 98%). Mean dose-length product for coronary CTA was 54 +/- 6 mGy . cm, the effective dose was 0.76 +/- 0.08 mSv (0.64 to 0.95 mSv).CONCLUSIONS In nonobese patients with a low and stable heart rate, prospectively ECG-triggered high-pitch spiral coronary CTA provides high diagnostic accuracy for the detection of coronary artery stenoses. (J Am Coll Cardiol Img 2011;4:328-37) (C) 2011 by the American College of Cardiology Foundation

Ziele: Ziel dieser Studie war es, strahleninduzierte DNA-Doppelstrangbrüche (DSB) in Blutlymphozyten von Patienten zu vergleichen, die sich einer koronaren CT-Angiographie (CTA) mit einem helikalen High-Pitch-, einem helikalen Low-Pitch- oder einem sequentiellen Untersuchungsprotokoll unterzogen. Methode: 66 Patienten wurden mit verschiedenen Protokollen an einem 64-Schicht-Dual-Source-, einem 128-Schicht-Single-Source- oder einem 128-Schicht-Dual-Source-CT untersucht (Low-pitch Spirale: 100–120kV, 320–438mAs/rot, Pitch 0,18–0,39, mit/ohne EKG-Pulsing, n=35; prospektiv EKG-getriggerte High-pitch Spirale: 100–120kV, 320–456mAs/rot., Pitch 3,2–3,4, n=19; prospektiv EKG-getriggerte Sequenz: 100–120kV, 320–370mAs/rot, n=12). Blutproben wurden vor und 30 Minuten nach der CTA entnommen und DSB wurden in isolierten Lymphozyten mit der Gamma-H2AX-Immunfluoreszenzmikroskopie quantifiziert. Ergebnis: Vor der Exposition lagen die Werte zwischen 0,04 und 0,16 DSB/Zelle, innerhalb von 30 Minuten steigen sie signifikant auf 0,09 bis 0,80 DSB/Zelle an (p<0,0001). Die Differenz entsprach den CT-induzierten DSB (0,01–0,71 DSB/Zelle) und korrelierte signifikant mit der mittels Koversionsfaktor abgeschätzten effektiven Dosis (ρ=0,90, p<0,00001). Sowohl nach der prospektiv getriggerten Sequenz (0,10 DSB/Zelle, 176 mGy*cm, p<0,00001) als auch nach der High-Pitch-Spirale (0,03 DSB/Zelle, 109 mGy*cm, p<0,00001) lag der Median des Dosislängenprodukts und der DSB-Werte signifikant niedriger als nach der Low-Pitch-Spirale (0,34 DSB/Zelle, 828 mGy*cm). Eine Reduktion der Röhrenspannung führte bei verschiedenen Protokollen zu einer signifikanten Reduktion von Dosislängenprodukt und DNA-Schäden (jeweils p<0,05). Schlussfolgerung: Bei der koronaren CTA haben die Untersuchungsprotokolle einen signifikanten Einfluss auf die Anzahl an strahleninduzierten DNA-Schäden. Mithilfe der Gamma-H2AX-Immunfluoreszenzmikroskopie können diesbezüglich verschiedene Protokolle, aber auch CT-Scanner verschiedener Generationen verglichen werden.

Introduction Chylothorax caused by chronic lymphocytic leukemia is very rare and the best therapeutic approach, especially the role of modern immunochemotherapy, is not yet defined. Case presentation We present the case of a 65-year-old male Caucasian patient with right-sided chylothorax caused by a concomitantly diagnosed chronic lymphocytic leukemia. As first-line treatment four cycles of an immunochemotherapy, consisting of fludarabine, cyclophosphamide and rituximab were administered. In addition, our patient received total parenteral nutrition for the first two weeks of treatment. Despite the very good clinical response of the lymphoma to treatment, the chylothorax persisted and percutaneous radiotherapy of the thoracic duct was applied. However, eight weeks after the radiotherapy the chylothorax still persisted and our patient agreed to a surgical intervention. A ligation of the thoracic duct via a muscle sparing thoracotomy was performed, resulting in a complete cessation of the pleural effusion. Apart from the first two weeks our patient was treated on an out-patient basis for nearly six months. Conclusion In this case of chylothorax caused by chronic lymphocytic leukemia, immunochemotherapy in combination with conservative treatment, and even consecutive radiotherapy, were not able to stop pleural effusion, despite the very good clinical response of the chronic lymphocytic leukemia to treatment. Out-patient management using repetitive thoracocenteses can be safe as bridging until definitive surgical ligation of the thoracic duct.

PURPOSE:An extensive number of protocols have been suggested to allow for functional diagnostics; however, no data is available about the minimal amount of contrast medium to achieve reliable imaging properties. None of the plethora of existing studies report a rational why the specific concentration was chosen. MATERIALS AND METHODS:A total of 40 patients were included in this prospective, controlled study. They were divided up into four equal groups getting a different concentration (10%, 20%, 30% or 40%) of a second contrast medium bolus. Corresponding septal and right ventricular ROIs were compared. A visual score was established. Coronary attenuation was measured in the right and left coronary artery. Streak artifacts in the right atrium/ventricle were assessed. RESULTS:In the 10% contrast medium (CM) group only in 5/10 (50%) patients full septal delineation was reached. In all other groups full septal visualization was obtained. No group showed a relevant difference of mean density measured in HU units of the left ventricle or the coronary arteries. All study groups except of group 1 (10% CM) showed streak artifacts in the right atrium. CONCLUSION:The dual flow protocol with a minimum concentration of 20% improves septal visualization as basis for left ventricular functional assessment, however, does not allow for reliable right ventricular or atrial visualization. There is no significant difference between the different concentration protocols in terms of coronary attenuation.

Objective: To evaluate, whether semi-automated vessel extraction and curved planar reformations ("automated vessel extraction") increases diagnostic accuracy in the detection of relevant coronary artery lesions compared to manual, interactive multiplanar interpretation ("manual approach").Materials and methods: 50 coronary CT angiography datasets were evaluated by four independent readers (two experienced, two novice) for the presence of stenoses exceeding 50% diameter reduction. One experienced and one novice reader each used the "manual approach" for cases 1-25 and "automated vessel extraction" for cases 26-50, while the other two readers used the complementary method. Results were compared to those of invasive coronary angiography.Results: Using the "manual approach", 37 of 42 stenoses were correctly detected by experienced as well as novice readers. 14 vs. 17 lesions were false positive (sensitivity 88%, specificity 91% vs. 89%, PPV 73% vs. 69%, NPV 97%, n.s.). Using "automated vessel extraction", experienced readers detected 35/42 stenoses compared to 31/42 for novice readers. 7 vs. 11 lesions were missed and 17 vs. 15 false-positive lesions reported (sensitivity 83% vs. 74%, specificity 89% vs. 90%, PPV 67%, NPV 95% vs. 93%, n.s.). In patient-based analysis, for novice readers sensitivity was higher using the "manual approach" (97%, 29/30 pts. vs. 80%, 24/30 pts., p = 0.069).Conclusions: Semi-automated vessel extraction and curved multiplanar reconstructions do not improve the diagnostic accuracy of coronary CT angiography compared to the use of interactive multiplanar reformations. Especially for less experienced readers, the use of automatically rendered curved multiplanar reconstructions alone cannot be recommended. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

Ziel: Liefert ein System zur digitalen Vollfeldmammografie (FFDM), das mit einem neuartigen Doppelschicht Selen Detektor arbeitet, einen Beitrag zu einer erhöhten Sensitivität und Spezifität der digitalen Mammografie?

AIMS:We evaluated the feasibility and image quality of a new scan mode for coronary computed tomography angiography (CTA) with an effective dose of less than 1 mSv.METHODS AND RESULTS:In 50 consecutive patients (body weight <or= 100 kg, sinus rhythm <or=60 b.p.m. after pre-medication, coronary CTA was performed using a dual-source CT system with 2 x 128 x 0.6 mm collimation, 0.28 s rotation time, a pitch of 3.2 or 3.4, 100 kV tube voltage and current of 320 mA s. Data acquisition was prospectively triggered at 60% of the R-R interval and completed within one cardiac cycle. Image quality was evaluated using a four-point scale (1 = absence of any artefacts to 4 = uninterpretable). In all 50 patients, imaging was successful. Mean duration of data acquisition was 258 +/- 20 ms. Mean dose-length product was 62 +/- 5 mGy cm, the effective dose was 0.87 +/- 0.07 mSv (0.78-0.99 mSv). Of the 742 coronary artery segments, 94% had an image quality score of 1, 5.0% a score of 2, 0.9% a score of 3, and 4 segments (0.5%) were 'uninterpretable'.CONCLUSION:In non-obese patients with a low and stable heart rate, prospectively ECG-triggered high-pitch spiral coronary CTA provides excellent image quality at a consistent dose below 1.0 mSv.