Clinical images: Muscle sarcoidosis demonstrated on positron emission tomography

Abstract Background: The dedicated breast positron emission tomography (dbPET) scanner (Elmamo, Shimadzu, Kyoto, Japan) has received approval from the Japanese Pharmaceutical Affairs Law and is commercially available in Japan. We assessed image quality of dbPET at the detector's edge, where the mammary glands near the chest wall are located in phantom and clinical studies.Methods: A breast phantom with four spheres (16, 10, 7.5, and 5 mm diameter) was filled with 18F-fluorodeoxyglucose solution (sphere-to-background ratio, 8:1). The spheres occupied five different positions from the top edge to the centre of the detector and were scanned for 5 min in each position. Reconstructed images were visually evaluated, and the contrast-to-noise ratio (CNR), contrast recovery coefficient (CRC) for the 5-mm sphere, and coefficient of variation of the background (CVB) were calculated. Subsequently, clinical images obtained with standard spine PET/CT and prone dbPET were retrospectively analysed. Tumour-to-background ratios (TBRs) between breast cancer near the chest wall (close to the detector’s edge; peripheral group) and at other locations (non-peripheral group) were compared. The TBR of each lesion was compared between dbPET and PET/computed tomography (CT).Results: Closer to the detector’s edge, the CNR and CRC decreased while the CVB increased in the phantom study. The disadvantages of this placement were visually confirmed. Regarding clinical images, TBR of dbPET was significantly higher than that of PET/CT in both the peripheral (12.38±6.41 vs 6.73±3.5, p=0.0006) and non-peripheral (12.44±5.94 vs 7.71±7.1, p=0.0183) groups. There was no significant difference in TBR of dbPET between the peripheral and non-peripheral groups (12.4±6.4 vs 12.4±5.9, p=0.8261).Conclusion: The phantom study revealed poorer image quality closer to the detector edge at a depth of <2 cm from the detector's edge than at other more central parts. In clinical studies, however, the visibility of breast lesions with dbPET was the same regardless of the lesion position, and it was higher than that in PET/CT. dbPET has a great potential for detecting breast lesions near the chest wall if they are at least 2 cm from the edge of the FOV, even in young women with small breasts.

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Clinical Images: Takayasu arteritis diagnosed by positron emission tomography

Arthritis & Rheumatism ◽

10.1002/art.22723 ◽

2007 ◽

Vol 56 (7) ◽

pp. 2466-2466 ◽

Cited By ~ 1

Author(s):

Kunihiro Yamaoka ◽

Kazuyoshi Saito ◽

Shingo Nakayamada ◽

Makiko Yamamoto ◽

Yoshiya Tanaka

Keyword(s):

Positron Emission Tomography ◽

Takayasu Arteritis ◽

Emission Tomography ◽

Clinical Images ◽

Positron Emission

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Evaluation of image quality at the detector’s edge of dedicated breast positron emission tomography: Can small breast cancer near the chest wall be detected ?

10.21203/rs.3.rs-21524/v1 ◽

2020 ◽

Author(s):

Yoko Satoh ◽

Utaroh Motosugi ◽

Masamichi Imai ◽

Yoshie Omiya ◽

Hiroshi Onishi

Keyword(s):

Breast Cancer ◽

Positron Emission Tomography ◽

Image Quality ◽

Chest Wall ◽

Phantom Study ◽

Emission Tomography ◽

Clinical Images ◽

Positron Emission ◽

Pet Ct ◽

Significant Difference

Abstract Purpose : We assessed image quality of dedicated breast positron emission tomography (dbPET) at the detector's edge by phantom and clinical studies.Methods: A breast phantom with four spheres (16, 10, 7.5, and 5 mm in diameter) was filled with 18 F-fluorodeoxyglucose solution of sphere-to-background ratio was 8:1. It was positioned such that the spheres were five different positions from the top edge to the centre of the detector and scanned for 5 min in each position. Reconstructed images were visually evaluated, and % background variability ( %N 5mm ), % contrast ( %Q H ,5mm ), contrast-to-noise ratio ( Q H ,5mm / N 5mm ), and coefficient of variation of the background ( CV background ) were calculated. Next, tumour-to-background ratios (TBRs) between breast cancer near the chest wall (close to the detector’s edge; peripheral group) and at other locations (non-peripheral group) were compared. The TBR of each lesion was also compared between dbPET and PET/computed tomography (CT).Results: As closer to the detector’s edge, the %N 5mm and CV background increased and %Q H ,5mm and Q H ,5mm / N 5mm decreased in the phantom study. The disadvantages of this placement were visually confirmed. With regard to clinical images, TBR of dbPET was significantly higher than that of PET/CT in both the peripheral (12.1±6.2 vs. 6.5±3.4, p =0.0001) and non-peripheral (13.1±7.1 vs. 7.7±7.4, p =0.0004) groups. There was no significant difference in TBR of dbPET between the peripheral and non-peripheral groups (12.1±6.2 vs. 13.1±7.1, p= 0.6367).Conclusion : In the phantom study, the image quality decreased closer to the detector’s edge than at a depth of 1/8. In clinical studies, however, the lesion detectability of dbPET was the same even if the lesion was close to the detector’s edge or not, and it was higher than that in PET/CT. dbPET has a great potential for detecting breast lesions near the chest wall even in young women with small breasts.

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Evaluation of image quality at the detector’s edge of dedicated breast positron emission tomography

10.21203/rs.3.rs-21524/v2 ◽

2020 ◽

Author(s):

Yoko Satoh ◽

Utaroh Motosugi ◽

Masamichi Imai ◽

Yoshie Omiya ◽

Hiroshi Onishi

Keyword(s):

Positron Emission Tomography ◽

Image Quality ◽

Chest Wall ◽

Clinical Studies ◽

Phantom Study ◽

Emission Tomography ◽

Clinical Images ◽

Positron Emission ◽

Pet Ct ◽

Significant Difference

Abstract Background: We assessed image quality of dedicated breast positron emission tomography (dbPET) at the detector's edge by phantom and clinical studies.Methods: A breast phantom with four spheres (16, 10, 7.5, and 5 mm diameter) was filled with 18F-fluorodeoxyglucose solution (sphere-to-background ratio, 8:1). The spheres occupied five different positions from the top edge to the centre of the detector and were scanned for 5 min in each position. Reconstructed images were visually evaluated, and % background variability (%N5mm), % contrast (%QH,5mm), and contrast-to-noise ratio (QH,5mm/N5mm) for the 5 mm sphere; and coefficient of variation of the background (CVbackground) were calculated. Subsequently, clinical cases were analysed. Tumour-to-background ratios (TBRs) between breast cancer near the chest wall (close to the detector’s edge; peripheral group) and at other locations (non-peripheral group) were compared. The TBR of each lesion was compared between dbPET and PET/computed tomography (CT).Results: Closer to the detector’s edge, the %N5mm and CVbackground increased and %QH,5mm and QH,5mm/N5mm decreased in the phantom study. The disadvantages of this placement were visually confirmed. Regarding clinical images, TBR of dbPET was significantly higher than that of PET/CT in both the peripheral (12.1±6.2 vs. 6.5±3.4, p=0.0001) and non-peripheral (13.1±7.1 vs. 7.7±7.4, p=0.0004) groups. There was no significant difference in TBR of dbPET between the peripheral and non-peripheral groups (12.1±6.2 vs. 13.1±7.1, p=0.6367).Conclusion: The phantom study revealed poorer image quality closer to the detector edge at a depth of 1/8 of the axial field of view (FOV) than at other more central parts. In clinical studies, however, lesion detectability of dbPET was the same regardless of the lesion position, and it was higher than that in PET/CT. dbPET has a great potential for detecting breast lesions near the chest wall if they are within the FOV, even in young women with small breasts.

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