Comparison Between Low (3:1) and High (6:1) Pitch for Routine Abdominal/Pelvic Imaging With Multislice Computed Tomography

Sahani, Dushyant V.; Saini, Sanjay; D’Souza, Roy V.; O’Neill, Margaret; Prasad, Srinivasa R.; Kalra, Mannudeep K.; Halpern, Elkan F.; Müeller, Peter R.

doi:10.1097/00004728-200303000-00001

Cited by 14 publications

(9 citation statements)

References 8 publications

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“…The other available pitch selection on this scanner intended for fast volume coverage speed was not selected, since the objective of this study was simply to compare image quality as opposed to scanning time. It is worth pointing out, however, that a recent study by Sahani et al ( 16 ) showed no statistically significant differences in the overall image quality performance of the 3:1 or 6:1 pitch imaging techniques. However, side‐by‐side comparisons of images generated by both pitch selections showed superior quality with the images generated using a pitch of 3:1.…”

Section: Discussionmentioning

confidence: 86%

Comparative evaluation of image quality from three CT simulation scanners

McCann

Alasti

2004

J Applied Clin Med Phys

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Today, radiation therapy (RT) is moving toward increased radiation dose to the tumor as a result of 3D conformal RT (3DCRT) and intensity‐modulated RT (IMRT), which have been made possible by advances in volumetric‐based image planning with digital imaging systems such as computed tomography (CT). Treatment planning for such RT requires superior CT image quality. Our goal in this study was to evaluate and to compare the image quality of three unique CT simulation scanners available at our center for both single‐ and multiple‐slice helical scanners. These scanners included a conventional 70‐cm bore single‐slice scanner (Philips Medical Systems), a large 85‐cm bore single‐slice scanner (Philips Medical Systems), and a 70‐cm bore multislice scanner (GE Medical Systems). Image quality was evaluated in terms of image noise, low‐contrast detectability (LCD), limiting spatial resolution (modulation transfer function), and slice thickness accuracy in accordance with guidelines set out by the AAPM. A commercially available Catphan® phantom was used to characterize image quality for both axial and helical modes of scanning. We found that image quality was generally comparable for all scanners. Limiting spatial resolution and slice thickness accuracy were comparable for all three scanners for both scanning modes. The multislice unit was superior in terms of noise content, resulting in improved visualization of small, low‐contrast objects, which is of significant clinical importance, particularly for soft tissue delineation. In addition, the multislice unit optimizes volume coverage speed and longitudinal resolution without compromising image quality, a significant advantage for the radiation oncology environment.PACS numbers: 87.57.Ce, 87.59.Fm, 87.57.Nk

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Section: Discussionmentioning

confidence: 86%

Comparative evaluation of image quality from three CT simulation scanners

McCann

Alasti

2004

J Applied Clin Med Phys

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“…In particular, significant decrease in SNR and CNR could be a limitation in patients studied for the first time because of possible overlooking of pathologic findings in the abdominal aorta. Sahani et al (17) reported similar image quality for standard CTA and DS-CTA in abdominopelvic vessels; however, they did not explore quantitative metrics. Moreover, Russo et al (18) reported quantitative parameters of 128-slice scanner with high-speed rotation time for imaging thoracoabdominal aorta.…”

Section: Discussionmentioning

confidence: 99%

High-pitch dual-source CT angiography without ECG-gating for imaging the whole aorta: intraindividual comparison with standard pitch single-source technique without ECG-gating

Manna¹,

Silva²,

Cobelli³

et al. 2017

Diagn Interv Radiol

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C omputed tomography angiography (CTA) of the aorta is the reference method to investigate aortic disease and to follow up patients after surgical or endovascular aortic repair, either thoracic or abdominal. Thoracic aorta usually demands electrocardiography (ECG)-gated CTA to avoid motion artifacts related to cardiac cycle, notably for imaging aortic root and ascending segment (1). However, ECG-gating results in significantly increased radiation exposure, notably in case of low-pitch acquisition for retrospective reconstruction. Furthermore, ECG-gating technique is also related to significant increase of imaging time and volume of contrast agent.Dual-source (DS) hardware is a significant technological advance because it allows acquisition with exceptionally high-pitch and fast rotation speed, with substantial reduction of acquisition time and time resolution. For instance, DS-CTA with ECG-gating allows whole coronary imaging (scan length, 12-14 cm) in a single heart cycle with significant reduction in radiation dose and volume of contrast agent (2). Furthermore, DS-CTA with ECG-gating provides high quality images with minor motion artifacts also in imaging of whole thoracic aorta (scan length 20-30 cm) (3). Karlo et al. (4) demonstrated that high-pitch DS-CTA without ECG-gating provides diagnostic image quality of the aortic valve-aortic root complex similar to ECG-gated technique. Despite these advantages in acquisition of short vascular segments (e.g., coronary or thoracic aorta), the role of high-pitch DS-CTA in imaging the whole thoracoabdominal aorta still remains a challenge and a topic of debate (5-8) C A R D I O VA S C U L A R I MAG I N G O R I G I N A L A R T I C L E PURPOSEWe aimed to perform intraindividual comparison of computed tomography (CT) parameters, image quality, and radiation exposure between standard CT angiography (CTA) and high-pitch dual source (DS)-CTA, in subjects undergoing serial CTA of thoracoabdominal aorta. METHODSEighteen subjects with thoracoabdominal CTA by standard technique and high-pitch DS-CTA technique within 6 months of each other were retrieved for intraindividual comparison of image quality in thoracic and abdominal aorta. Quantitative analysis was performed by comparison of mean aortic attenuation, noise, signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR). Qualitative analysis was performed by visual assessment of motion artifacts and diagnostic confidence. Radiation exposure was quantified by effective dose. Image quality was apportioned to radiation exposure by means of figure of merit. RESULTSMean aortic attenuation and noise were higher in high-pitch DS-CTA of thoracoabdominal aorta, whereas SNR and CNR were similar in thoracic aorta and significantly lower in high-pitch DS-CTA of abdominal aorta (P = 0.024 and P = 0.016). High-pitch DS-CTA was significantly better in the first segment of thoracic aorta. Effective dose was reduced by 72% in high-pitch DS-CTA. CONCLUSIONHigh-pitch DS-CTA without electrocardiography-gating is an effective technique for...

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“…Rather, one might speculate that shorter acquisition times combined with appropriate contrast medium bolus timing enable capturing the vascular system during a phase of higher, more concentrated intralumi-nal contrast medium attenuation, despite lower contrast medium volumes, than with slower image acquisition and possible greater dilution of intravascular contrast medium. In patients undergoing abdominal, pelvic, or abdominopelvic imaging, Sahani et al [19] reported similar image quality using high-pitch or low-pitch technique. Factors affected by the pitch include effective section thickness, image noise, beam-hardening artifacts, image acquisition speed, and radiation dose [19,20].…”

Section: Apfaltrer Et Almentioning

confidence: 96%

“…In patients undergoing abdominal, pelvic, or abdominopelvic imaging, Sahani et al [19] reported similar image quality using high-pitch or low-pitch technique. Factors affected by the pitch include effective section thickness, image noise, beam-hardening artifacts, image acquisition speed, and radiation dose [19,20]. Lowering the pitch reduces the slice-broadening effect, minimizes helical artifacts, and lowers image noise [21,22].…”

Section: Apfaltrer Et Almentioning

confidence: 96%

Radiation Dose and Image Quality at High-Pitch CT Angiography of the Aorta: Intraindividual and Interindividual Comparisons With Conventional CT Angiography

Apfaltrer

Hanna

Schoepf

et al. 2012

American Journal of Roentgenology

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Comparison Between Low (3:1) and High (6:1) Pitch for Routine Abdominal/Pelvic Imaging With Multislice Computed Tomography

Abstract: Image quality with a high pitch (6:1) is acceptable for routine abdominal/pelvic CT.

Cited by 14 publications

References 8 publications

Comparative evaluation of image quality from three CT simulation scanners

Comparative evaluation of image quality from three CT simulation scanners

High-pitch dual-source CT angiography without ECG-gating for imaging the whole aorta: intraindividual comparison with standard pitch single-source technique without ECG-gating

Radiation Dose and Image Quality at High-Pitch CT Angiography of the Aorta: Intraindividual and Interindividual Comparisons With Conventional CT Angiography

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