Sialolipom der Glandula parotis

Zusammenfassung: Das Sialolipom ist eine relativ neue und seltene Lipomvariante der Speicheldrüsen, welche durch die Kombination von klassischer Lipommorphologie mit nichtneoplastischen duktuloazinären Speicheldrüsenanteilen gekennzeichnet ist. Inklusive des vorliegenden Falles wurden bislang 27Sialolipome publiziert, davon 14 in der Glandula parotis. Wir beschreiben die klinischen, radiologischen und pathomorphologischen Eigenschaften eines Sialolipoms der Ohrspeicheldrüse bei einem 43Jahre alten Patiente

Kardiale Niedrigdosis-Computertomographie

Cardiac CT has evolved to a robust and accurate imaging modality in the cardiac diagnostic armamentarium. However, technical developments had been accompanied with an overall increase in radiation exposure. In the last years, several technical developments and algorithms aimed at the reduction of radiation exposure in cardiac CT. The most relevant dose reduction strategies will be highlighted in this article including appropriate indications for cardiac CT, different ECG synchronization techniques, reduction of tube voltage, and high-pitch CT studies

Die Computertomographie bei der Bildgebung von Kindern mit kongenitalen Herzvitien

Zusammenfassung: Kongenitale Herzfehler sind die häufigsten kongenitalen Fehlbildungen. Echokardiographie und Katheterangiographie gelten allgemein als Goldstandard zur Abklärung angeborener Herzerkrankungen. Die Magnetresonanztomographie ist aufgrund ihrer Fähigkeit, Herzvitien morphologisch und funktionell zu charakterisieren, als ein wichtiges ergänzendes Verfahren anzusehen. Durch mehr und mehr dosissparende Untersuchungsprotokolle der neuesten Gerätegenerationen und eine gleichzeitig bessere zeitliche und räumliche Auflösung findet die Computertomographie zunehmend Eingang in die Abklärung kongenitaler Herzfehler. In der präoperativen Planung und der postoperativen Kontrolle erlaubt sie eine übersichtliche Darstellung komplexer Fehlbildung nicht nur des Herzens, sondern auch der pulmonalvenösen und -arteriellen Zirkulation sowie des systemischen Kreislaufs. Dieser Beitrag gibt eine Übersicht über die technischen Aspekte der kardialen CT und die Anpassung des Untersuchungsprotokolls an die zu erwartende Pathologie und das Alter des Kindes. Zudem werden die Möglichkeiten und Limitationen der unterschiedlichen dosissparenden Protokolle erläuter

The Toxic Effects of Cigarette Additives. Philip Morris' Project Mix Reconsidered: An Analysis of Documents Released through Litigation

Stanton Glantz and colleagues analyzed previously secret tobacco industry documents and peer-reviewed published results of Philip Morris' Project MIX about research on cigarette additives, and show that this research on the use of cigarette additives cannot be taken at face value

Mono- versus bisegment reconstruction algorithms for dual-source computed tomography coronary angiography.

OBJECTIVE: To compare the image quality of mono- versus bisegment reconstruction algorithms for dual-source computed tomography coronary angiography (CTCA). MATERIALS AND METHODS: Eighty consecutive patients (27 women; average age, 60 +/- 12 years) were randomly assigned to 2 different CTCA scanning protocols: 40 patients (group A) underwent dual-source CTCA with a heart rate (HR)-dependent pitch adaptation with datasets reconstructed using the monosegment algorithm; 40 patients (group B) underwent CTCA at a fixed pitch of 0.2 and datasets were reconstructed using both mono- and bisegment algorithms. The temporal resolution was 82 milliseconds for mono- and 42 to 83 milliseconds (58 +/- 14 milliseconds) for bisegment reconstruction, the latter depending on the HR during CTCA. Images were reconstructed in the reconstruction phase having least motion artifacts in the individual patient, primarily during mid-diastole at 70% of the R-R interval. The HR variability was defined as the standard deviation from the average HR. Two blinded observers independently assessed the image quality of each coronary segment using a 4-point scale (1: excellent to 4: nonevaluable). Effective radiation dose estimates were calculated. RESULTS: The overall image quality showed no significant differences between the 2 groups scanned with a fixed or a HR-adapted pitch (group A, score 1.21 +/- 0.63; group B, score 1.19 +/- 0.52). The overall image quality was superior when using monosegment (group A and B, score 1.21 +/- 0.63 and 1.19 +/- 0.52, respectively) when compared with the bisegment reconstruction algorithm (group B, score 1.33 +/- 0.72; P < 0.01). Image quality did not significantly correlate with average HR neither for monosegment (group A: r = 0.07; P = 0.35; group B: r = 0.06; P = 0.41) nor bisegment reconstructions (r = 0.07; P = 0.32). There was no significant correlation between image quality and HR variability using monosegment reconstructions (group A: r = 0.09; P = 0.22; group B: r = 0.05; P = 0.67), whereas a significant correlation was found for bisegment reconstructions (group B: r = 0.51; P < 0.01). The estimated effective radiation dose was significantly higher in group B (10.8 +/- 1.4 mSv) when compared with group A (9.0 +/- 0.8 mSv; P < 0.01). CONCLUSIONS: Although providing a higher temporal resolution at certain HRs, the use of bisegment reconstructions for dual-source CTCA does not result in an improved overall image quality when compared with the monosegment reconstruction algorithm

Sialolipom der Glandula parotis

Sialolipoma is a relatively new and rare variant of lipoma of the salivary glands characterized by the combination of classical lipoma morphology with non-neoplastic ductulo-acinary salivary tissue components. Including the presented case, 27 sialolipomas, 14 of them localized in the parotid gland, have been published. We describe the clinical, radiological and pathomorphological characteristics of a parotid sialolipoma in a 43-year-old man

Dual source CT coronary angiography in severely obese patients: trading off temporal resolution and image noise

OBJECTIVE: To assess in severely obese patients the subjective and objective image quality parameters and to estimate the radiation dose of dual-source computed tomography coronary angiography (CTCA), using 3 different protocols. MATERIALS AND METHODS: Dual-source CTCA was performed in 60 patients (30 women; mean age 58 +/- 7 years) suffering from obesity class II or higher (body mass index [BMI] >35 kg/sq m). Twenty patients were examined with a standard CTCA protocol at 120 kV/350 mAs (protocol A), 20 patients with a CTCA protocol at 140 kV/350 mAs (protocol B), and 20 patients at 140 kV/350 mAs with a dedicated obesity protocol (protocol C), that allows the additional data sampling by expanding the data acquisition for each tube from a quarter to a half rotation, permitting to trade off temporal resolution and image noise. Two blinded observers independently assessed the image quality of each coronary segment, using a 4-point scale (1: excellent-4: nondiagnostic) and measured the different image parameters (image noise, signal-to-noise ratio [SNR], and contrast-to-noise ratio [CNR]). Radiation dose estimates were calculated. RESULTS: The average BMI was 46.3 +/- 8.3 kg/sq m (range, 36.8-69.6 kg/sq m). Subjective image quality (1.55 +/- 0.73) was significantly better in protocol C when compared with protocol A (2.46 +/- 0.76; P < 0.01) and protocol B (2.12 +/- 0.87; P < 0.017). There was a significantly lower rate of coronary artery segments with nondiagnostic image quality when using the obesity protocol C (1.5%; 4/262) compared with that obtained when using protocol A (7.8%; 22/280; P < 0.01) and protocol B (4.4%; 12/275; P < 0.017). Image noise was significantly lower in protocol C (31.8 +/- 5.0 HU) when compared with group A (43.5 +/- 4.7 HU; P < 0.001) and B (36.8 +/- 5.5 HU; P < 0.01). SNR and CNR were significantly higher in group C (13.8 +/- 2.4 and 23.1 +/- 2.8) compared with group A (10.6 +/- 1.7 and 15.1 +/- 3.2; each P < 0.001) and group B (12.0 +/- 2.0 and 18.8 +/- 3.1; each P < 0.01). The estimated effective radiation dose of the obesity protocol C (15.6 +/- 0.9 mSv) was significantly higher when compared with that in protocol A (10.1 +/- 0.8 mSv; P < 0.01), but not significantly different from that in protocol B (13.3 +/- 0.8 mSv; P = 0.022). CONCLUSIONS: Use of an obesity protocol in dual-source CTCA in severely obese patients significantly improves image quality, but goes along with a higher radiation dose

Die Computertomographie bei der Bildgebung von Kindern mit kongenitalen Herzvitien

Congenital heart diseases are the most common congenital abnormalities of development. In general, echocardiography and cardiac catheter angiography are considered the gold standard for the evaluation of congenital heart disease. Cardiac magnetic resonance imaging has become an important supplementary imaging modality because of its ability to provide an accurate morphological and functional evaluation. The role of cardiac computed tomography in the imaging of patients with congenital heart disease is becoming increasingly more important due to the development of low radiation dose protocols and improvements in the spatial and temporal resolution. In the preoperative depiction and follow-up after surgical repair of congenital heart diseases, cardiac computed tomography provides detailed information of the heart, the venous and arterial pulmonary circulation as well as systemic arteries. This article reviews the technical aspects of cardiac CT and the modification of examination protocols according to the expected pathology and patient age. The potentials and limitations of the various radiation dose reduction strategies are outlined