First, we applied phase-by-phase attenuation correction (P-AC), where every 4D-PET respiration phase frame was corrected with the corresponding 4D-CT respiration phase frame.
We have tested the use of the inhale CT, exhale CT and untriggered 3D-CT for attenuation correction and compared this to the respiration-averaged phase-by-phase attenuation correction, which we chose as our gold standard.
It has been suggested that delayed phase images are useful for differentiating AIP and pancreatic cancer, with higher delayed phase attenuation values seen in the former [15, 19, 20].
These effects are modest on average but can be substantial in extreme cases; the overall SUVmax difference in the tumour between the use of phase-by-phase attenuation correction or a 3D-CT dataset in the tumour ranged up to 20%.
Although the mantle Sn phase was clearly observed with propagation in western Japan (Figure 4c) and from the Korean Peninsula to Kyushu (Figure 4b), Sn phase attenuation was very strong in northern Japan and along the path across the Sea of Japan (Figure 4a).
In the evaluation of an adrenal mass using CT, the following features are important to consider: size of the lesion, local extent of the lesion, degree of enhancement on various imaging phases, attenuation of lesion prior to contrast administration, and attenuation of the various components of the lesion.
The mean diameters, arterial, portal, and delayed phase attenuations, and washout of HCC were not significantly different (P > 0.05).
The mean arterial, portal, and delayed phase attenuations, and the washout of HCC lesions of HBV-positive and -negative patients, are shown in Table 5.
In this study, there was no difference between imaging appearance (mean arterial, portal, and delayed phase attenuations and washout degrees) of HCC lesions in HBV-positive and -negative patients.
With respect to the condition used in this study we conclude that these miRNAs play important role in the pollen thermotolerance, as being regulated in the recovery phase, during the attenuation phase of heat stress response.
