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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.

Ozdoba C, Slotboom J, Schroth G, Ulzheimer S, Kottke R, Watzal H, Weisstanner C - Clin Neuroradiol (2014)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: University Institute of Diagnostic and Interventional Neuroradiology, University of Bern/Inselspital, Freiburgstrasse 4, 3010, Bern, Switzerland.

ABSTRACT

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 (CTDI(vol)) 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: CTDI(Vol) 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.

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Related in: MedlinePlus

Typical region-of-interest measurements in the frontal cortex and white matter (diameter of region of interest: 5 mm). Mittelwert  mean, Abweichung  standard deviation
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Fig2: Typical region-of-interest measurements in the frontal cortex and white matter (diameter of region of interest: 5 mm). Mittelwert  mean, Abweichung  standard deviation

Mentions: The ‘statistics/circle’ function of our hospital’s PACS (Sectra Imtec AB, Stockholm, Sweden; IDS 5, Release 11.4.1) was used to determine Hounsfield values in regions of interest in the frontal cortex and adjacent white matter. The same-size region of interest was used in all patients; measured mean values and standard deviation (SD) were used for subsequent analysis. A typical example of the regions used is shown in Fig. 2.


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.

Ozdoba C, Slotboom J, Schroth G, Ulzheimer S, Kottke R, Watzal H, Weisstanner C - Clin Neuroradiol (2014)

Typical region-of-interest measurements in the frontal cortex and white matter (diameter of region of interest: 5 mm). Mittelwert  mean, Abweichung  standard deviation
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3936131&req=5

Fig2: Typical region-of-interest measurements in the frontal cortex and white matter (diameter of region of interest: 5 mm). Mittelwert  mean, Abweichung  standard deviation
Mentions: The ‘statistics/circle’ function of our hospital’s PACS (Sectra Imtec AB, Stockholm, Sweden; IDS 5, Release 11.4.1) was used to determine Hounsfield values in regions of interest in the frontal cortex and adjacent white matter. The same-size region of interest was used in all patients; measured mean values and standard deviation (SD) were used for subsequent analysis. A typical example of the regions used is shown in Fig. 2.

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: University Institute of Diagnostic and Interventional Neuroradiology, University of Bern/Inselspital, Freiburgstrasse 4, 3010, Bern, Switzerland.

ABSTRACT

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 (CTDI(vol)) 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: CTDI(Vol) 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.

Show MeSH
Related in: MedlinePlus