M2 Shintaro Funabasama
Perfusion CT is an application, in which a quantitative map of tissue perfusion is created from dynamic CT data and displayed by means of a color scale. This technique was first presented by Miles et al. in 1991. However, this technique is not yet widely available, since computer software for this technique has not been widely distributed.We developed software for creating perfusion CT images on a personal computer (PC). We have applied this technique to variable upper abdominal diseases, and image quality of arterial and portal perfusion CT was visually assessed. we used to use one compartment model as a perfusion analysis method. However, the method is not enough to obtain accurate and detailed data of liver blood circulation. Therefore, as a new method, we use two compartment model to more accurate data of liver perfusion images.
The purpose of our study is to develop software for creating quantitative maps of arterial and portal perfusion of the upper abdominal organs on personal computer (PC). The image quality of these perfusion CT images was visually evaluated.
Materials and Methods: The study population consisted of 58 patients (38 men and 20 women; age, 63.9+/-11.9 years old; range, 22-85) with variable diseases of the upper abdomen, and 91 single-slice dynamic CT data were obtained. The data was transferred on line to PC, and quantitative maps of arterial and portal perfusion were created using maximum-slope method. Perfusion CT images were reviewed by a radiologist and a radiation technologist, and the image quality was determined according to a four-step scoring system (1=good quality, 2=moderate, 3=poor, 4=images could not be created).
Results: Arterial perfusion CT images could be created in 81 (89.0 %) of 91 examinations, and 74 images (81.3 %)were determined scored as 1 or 2. Portal perfusion CT images could be created in 60 (68.2 %) of 88 examinations, in which a portal trunk was included in the slice, and 37 images (42.0 %) were scored as 1 or 2. Patient motion during dynamic CT sequence resulted in poor image quality in 7 arterial and 27 portal perfusion CT.
Conclusion: Perfusion CT can provide quantitative perfusion maps combined with good anatomical detail in one image, although patient movement frequently degrades image quality in portal perfusion CT.
Keywords: Perfusion CT; Dynamic CT; Upper abdomen; Application software.
Next Trial: We are planning to make more accurate CT perfusion images with using Multidetector CT.
Free Software: You can download my perfusion software which is using our research for free. Please try to use the software. the address is below.