Dose Reduction in Standard Head CT: First Results from a New Scanner Using Iterative Reconstruction and a New Detector Type in Comparison with Two Previous Generations of Multi-slice CT

Purpose: Computed tomography (CT) accounts for more than half of the total radiation exposure from medical procedures, which makes dose reduction in CT an effective means of reducing radiation exposure. We analysed the dose reduction that can be achieved with a new CT scanner [Somatom Edge (E)] that incorporates new developments in hardware (detector) and software (iterative reconstruction). Methods: We compared weighted volume CT dose index (CTDIvol) and dose length product (DLP) values of 25 consecutive patients studied with non-enhanced standard brain CT with the new scanner and with two previous models each, a 64-slice 64-row multi-detector CT (MDCT) scanner with 64 rows (S64) and a 16-slice 16-row MDCT scanner with 16 rows (S16). We analysed signal-to-noise and contrast-to-noise ratios in images from the three scanners and performed a quality rating by three neuroradiologists to analyse whether dose reduction techniques still yield sufficient diagnostic quality. Results: CTDIVol of scanner E was 41.5 and 36.4 % less than the values of scanners S16 and S64, respectively; the DLP values were 40 and 38.3 % less. All differences were statistically significant (p < 0.0001). Signal-to-noise and contrast-to-noise ratios were best in S64; these differences also reached statistical significance. Image analysis, however, showed "non-inferiority” of scanner E regarding image quality. Conclusions: The first experience with the new scanner shows that new dose reduction techniques allow for up to 40 % dose reduction while still maintaining image quality at a diagnostically usable level

Calcium scoring using 64-slice MDCT, dual source CT and EBT: a comparative phantom study

Purpose Assessment of calcium scoring (Ca-scoring) on a 64-slice multi-detector computed tomography (MDCT) scanner, a dual-source computed tomography (DSCT) scanner and an electron beam tomography (EBT) scanner with a moving cardiac phantom as a function of heart rate, slice thickness and calcium density. Methods and materials Three artificial arteries with inserted calcifications of different sizes and densities were scanned at rest (0 beats per minute) and at 50–110 beats per minute (bpm) with an interval of 10 bpm using 64-slice MDCT, DSCT and EBT. Images were reconstructed with a slice thickness of 0.6 and 3.0 mm. Agatston score, volume score and equivalent mass score were determined for each artery. A cardiac motion susceptibility (CMS) index was introduced to assess the susceptibility of Ca-scoring to heart rate. In addition, a difference (Δ) index was introduced to assess the difference of absolute Ca-scoring on MDCT and DSCT with EBT. Results Ca-score is relatively constant up to 60 bpm and starts to decrease or increase above 70 bpm, depending on scoring method, calcification density and slice thickness. EBT showed the least susceptibility to cardiac motion with the smallest average CMS-index (2.5). The average CMS-index of 64-slice MDCT (9.0) is approximately 2.5 times the average CMS-index of DSCT (3.6). The use of a smaller slice thickness decreases the CMS-index for both CT-modalities. The Δ-index for DSCT at 0.6 mm (53.2) is approximately 30% lower than the Δ-index for 64-slice MDCT at 0.6 mm (72.0). The Δ-indexes at 3.0 mm are approximately equal for both modalities (96.9 and 102.0 for 64-slice MDCT and DSCT respectively). Conclusion Ca-scoring is influenced by heart rate, slice thickness and modality used. Ca-scoring on DSCT is approximately 50% less susceptible to cardiac motion as 64-slice MDCT. DSCT offers a better approximation of absolute calcium score on EBT than 64-slice MDCT when using a smaller slice thickness. A smaller slice thickness reduces the susceptibility to cardiac motion and reduces the difference between CT-data and EBT-data. The best approximation of EBT on CT is found for DSCT with a slice thickness of 0.6 mm

Coronary artery calcium screening: current status and recommendations from the European Society of Cardiac Radiology and North American Society for Cardiovascular Imaging

Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multi-detector CT is discussed

Digitale Kompetenzen für Medizinstudierende - qualitative Evaluation des Curriculum 4.0 "Medizin im digitalen Zeitalter"

Introduction: The digital transformation has far-reaching implications for the qualification profile of medical students, which have not been addressed in medical studies so far.Teaching concept: The competence-oriented blended learning curriculum "Medicine in the digital age" has been implemented at Mainz University Medical Centre since 2017. It represents a curricular reform project of the "Curriculum 4.0" program (Stifterverband). In six modules, the qualification requirements for digital skills are addressed. Evaluation Methodology: The qualitative evaluation of the course concept took place in the form of semi-structured interviews. All 58 participants from five courses were interviewed. Results: Using the "Qualitative Content Analysis" according to Philipp Mayring, the statements were divided into deductive main categories (process, content, methodology, learning success, learning experience and conclusion). The results reflect the student's view of the curriculum and the current qualification needs that still need to be specialised.Discussion: The didactic teaching of digital skills is a relevant and highly topical component of the further development of medical studies. In this development, the focus is not only on technological skills, but also on theEinleitung: Die digitale Transformation hat weitreichende Implikationen für das Qualifizierungsprofil von Medizinstudierenden, welche bisher im Medizinstudium nicht adressiert wurden.Lehrkonzept: Das kompetenzorientierte Blended-Learning-Curriculum "Medizin im digitalen Zeitalter" wurde seit 2017 als curriculares Reformprojekt im Rahmen des Förderprogramms "Curriculum 4.0" des Stifterverbandes an der Universitätsmedizin Mainz implementiert. In sechs Modulen soll der Qualifizierungsbedarf an digitalen Kompetenzen adressiert werden. Evaluationsmethodik: Die qualitative Evaluation des Kurskonzepts erfolgte in Form semi-strukturierter Interviews. Hierbei konnten alle 58 Teilnehmenden aus fünf Kursen befragt werden. Ergebnisse: Anhand der "Qualitativen Inhaltsanalyse" nach Philipp Mayring wurden die Aussagen in deduktiv gebildete Hauptkategorien (Ablauf, Inhalt, Methodik, Lernerfolg, Lernerlebnis und Fazit) unterteilt. Die Ergebnisse spiegeln die studentische Sichtweise auf das Curriculum und des aktuell noch zu spezifizierenden Qualifizierungsbedarfs wider.Diskussion: Die didaktische Vermittlung digitaler Kompetenzen ist ein relevanter und hochaktueller Bestandteil der Weiterentwicklung des Medizinstudiums. Bei dieser Entwicklung stehen nicht nur die technologischen Kompetenzen, sondern insbesondere auch die Reflexion der fachlichen, rechtlichen und ethischen Zusammenhänge sowie der Umgang mit Veränderungsprozessen im Fokus

Dose Reduction in Standard Head CT: First Results from a New Scanner Using Iterative Reconstruction and a New Detector Type in Comparison with Two Previous Generations of Multi-slice CT

PURPOSE Computed tomography (CT) accounts for more than half of the total radiation exposure from medical procedures, which makes dose reduction in CT an effective means of reducing radiation exposure. We analysed the dose reduction that can be achieved with a new CT scanner [Somatom Edge (E)] that incorporates new developments in hardware (detector) and software (iterative reconstruction). METHODS We compared weighted volume CT dose index (CTDIvol) and dose length product (DLP) values of 25 consecutive patients studied with non-enhanced standard brain CT with the new scanner and with two previous models each, a 64-slice 64-row multi-detector CT (MDCT) scanner with 64 rows (S64) and a 16-slice 16-row MDCT scanner with 16 rows (S16). We analysed signal-to-noise and contrast-to-noise ratios in images from the three scanners and performed a quality rating by three neuroradiologists to analyse whether dose reduction techniques still yield sufficient diagnostic quality. RESULTS CTDIVol of scanner E was 41.5 and 36.4 % less than the values of scanners S16 and S64, respectively; the DLP values were 40 and 38.3 % less. All differences were statistically significant (p < 0.0001). Signal-to-noise and contrast-to-noise ratios were best in S64; these differences also reached statistical significance. Image analysis, however, showed "non-inferiority" of scanner E regarding image quality. CONCLUSIONS The first experience with the new scanner shows that new dose reduction techniques allow for up to 40 % dose reduction while still maintaining image quality at a diagnostically usable level