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Stomach virtual non-enhanced CT with second-generation, dual-energy CT: a preliminary study.

Shi L, Yan F, Pan Z, Liu B, Liu H, Wang B, Zhang H, Yu Y - PLoS ONE (2014)

Bottom Line: Lower noise was found for VNE images than TNE images (P<0.01).Image quality of VNE was diagnostic but lower than that of TNE (P<0.01).The dose reduction achieved by omitting the TNE acquisition was 21.40 ± 4.44%.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.

ABSTRACT

Objectives: To compare the true non-enhanced (TNE) and virtual non-enhanced (VNE) data sets in patients who underwent gastric preoperative dual-energy CT (DECT) and to evaluate potential radiation dose reduction by omitting a TNE scan.

Methods: A total of 74 patients underwent gastric DECT. The mean CT values, length, image quality and effective radiation doses for VNE and TNE images were compared.

Results: There was no statistical difference in maximal thickness of gastric tumors and maximal diameter of enlarged lymph nodes among the TNE and VNE images (P>0.05). The mean CT value differences between TNE and VNE were statistically significant for all tissue types, except for aorta attenuation measurements (P<0.05), but the absolute differences were under 10 HU. Lower noise was found for VNE images than TNE images (P<0.01). Image quality of VNE was diagnostic but lower than that of TNE (P<0.01). The dose reduction achieved by omitting the TNE acquisition was 21.40 ± 4.44%.

Conclusion: VNE scan may potentially replace TNE as part of a multi-phase gastric preoperative staging imaging protocol with consequent saving in radiation dose.

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Related in: MedlinePlus

Excluded relevant anatomy.The yellow circle relates to the smaller (33 cm) field of view of the smaller detector. Iodine maps and subsequent iodine subtraction to create the virtual non-enhanced images can only be performed within the circle. In larger patients (>40 cm actual body diameter) or patients with improper position important anatomy may be excluded from the subtraction. In this example the lateral aspect of the right lobe of the liver fails to ‘become unenhanced’ (arrows).
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pone-0112295-g006: Excluded relevant anatomy.The yellow circle relates to the smaller (33 cm) field of view of the smaller detector. Iodine maps and subsequent iodine subtraction to create the virtual non-enhanced images can only be performed within the circle. In larger patients (>40 cm actual body diameter) or patients with improper position important anatomy may be excluded from the subtraction. In this example the lateral aspect of the right lobe of the liver fails to ‘become unenhanced’ (arrows).

Mentions: The subjective image quality scores of the three non-enhanced CT image serials (TNE, VNEA and VNEP) were 4.93±0.3, 4.15±0.7 and 4.4±0.6, respectively. All VNE images were rated as score 3 or above, indicating that all VNE images were acceptable for diagnosis purpose (Fig. 4). Image quality of both VNE images was lower than that of TNE images (P<0.01), while image quality of VNEP was higher than that of VNEA (P<0.01). Sixty-two (83.8%, 62/74) VNEA images and seventy-one (95.9%, 71/74) VNEP images were regarded as having the potential to replace TNE images by two experienced abdominal radiologists (Table 2). Overshooting artifact detected at the gas-fluid level was more obvious in VNE images than TNE images in 3 cases (Fig. 5). In addition, only one VNE data sets excluded relevant anatomy which was scored 2 (1–25% excluded) (Fig. 6).


Stomach virtual non-enhanced CT with second-generation, dual-energy CT: a preliminary study.

Shi L, Yan F, Pan Z, Liu B, Liu H, Wang B, Zhang H, Yu Y - PLoS ONE (2014)

Excluded relevant anatomy.The yellow circle relates to the smaller (33 cm) field of view of the smaller detector. Iodine maps and subsequent iodine subtraction to create the virtual non-enhanced images can only be performed within the circle. In larger patients (>40 cm actual body diameter) or patients with improper position important anatomy may be excluded from the subtraction. In this example the lateral aspect of the right lobe of the liver fails to ‘become unenhanced’ (arrows).
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4231030&req=5

pone-0112295-g006: Excluded relevant anatomy.The yellow circle relates to the smaller (33 cm) field of view of the smaller detector. Iodine maps and subsequent iodine subtraction to create the virtual non-enhanced images can only be performed within the circle. In larger patients (>40 cm actual body diameter) or patients with improper position important anatomy may be excluded from the subtraction. In this example the lateral aspect of the right lobe of the liver fails to ‘become unenhanced’ (arrows).
Mentions: The subjective image quality scores of the three non-enhanced CT image serials (TNE, VNEA and VNEP) were 4.93±0.3, 4.15±0.7 and 4.4±0.6, respectively. All VNE images were rated as score 3 or above, indicating that all VNE images were acceptable for diagnosis purpose (Fig. 4). Image quality of both VNE images was lower than that of TNE images (P<0.01), while image quality of VNEP was higher than that of VNEA (P<0.01). Sixty-two (83.8%, 62/74) VNEA images and seventy-one (95.9%, 71/74) VNEP images were regarded as having the potential to replace TNE images by two experienced abdominal radiologists (Table 2). Overshooting artifact detected at the gas-fluid level was more obvious in VNE images than TNE images in 3 cases (Fig. 5). In addition, only one VNE data sets excluded relevant anatomy which was scored 2 (1–25% excluded) (Fig. 6).

Bottom Line: Lower noise was found for VNE images than TNE images (P<0.01).Image quality of VNE was diagnostic but lower than that of TNE (P<0.01).The dose reduction achieved by omitting the TNE acquisition was 21.40 ± 4.44%.

View Article: PubMed Central - PubMed

Affiliation: Department of Radiology, Ruijin Hospital affiliated to Shanghai Jiaotong University School of Medicine, Shanghai, China.

ABSTRACT

Objectives: To compare the true non-enhanced (TNE) and virtual non-enhanced (VNE) data sets in patients who underwent gastric preoperative dual-energy CT (DECT) and to evaluate potential radiation dose reduction by omitting a TNE scan.

Methods: A total of 74 patients underwent gastric DECT. The mean CT values, length, image quality and effective radiation doses for VNE and TNE images were compared.

Results: There was no statistical difference in maximal thickness of gastric tumors and maximal diameter of enlarged lymph nodes among the TNE and VNE images (P>0.05). The mean CT value differences between TNE and VNE were statistically significant for all tissue types, except for aorta attenuation measurements (P<0.05), but the absolute differences were under 10 HU. Lower noise was found for VNE images than TNE images (P<0.01). Image quality of VNE was diagnostic but lower than that of TNE (P<0.01). The dose reduction achieved by omitting the TNE acquisition was 21.40 ± 4.44%.

Conclusion: VNE scan may potentially replace TNE as part of a multi-phase gastric preoperative staging imaging protocol with consequent saving in radiation dose.

Show MeSH
Related in: MedlinePlus