Pancreatic perfusion imaging method that reduces radiation dose and maintains image quality by combining volumetric perfusion CT with multiphasic contrast enhanced-CT.
OBJECTIVES
The aim of this study is to propose and evaluate a new method of volumetric perfusion computed tomography (PCT) incorporated into pancreatic multiphasic contrast enhanced (CE)-CT in the clinical setting.


METHODS
In this ethically approved study, PCT was incorporated into our existing scanning protocol in 17 patients and effective doses related to PCT were evaluated. CT values and signal-to-noise ratio (SNR) of anatomical structure were compared in diagnostic images that were acquired using 320-detector volumetric scan mode and 64-detector helical scan mode. In addition, focal lesion depiction was qualitatively assessed in the two groups. Perfusion parameters in normal pancreas were measured by two radiologists and the interobserver-reliability was assessed.


RESULTS
The effective dose of PCT was 5.1 ± 0.3 mSv. The actual effective dose (AED) including the dose used in volumetric scans for diagnostic imaging was 22.8 ± 5.3 mSv and the putative effective dose (PED) was 21.9 ± 9.1 mSv on average. There was no significant difference between AED and PED (p = 0.404). Compared with conventional helical scans, volumetric scans did not decrease CT values or SNR, but rather significantly increased those of the aorta in the arterial phase. Both groups had acceptable qualitatively assessed image quality with no significant difference in the depiction of each structure. There was almost perfect interobserver agreement in the measurement of perfusion parameters (mean ICCs > 0.9).


CONCLUSIONS
Our scanning protocol for pancreatic perfusion CT provides high-quality images while requiring lower radiation doses than conventional methods.
['Konno|Yoshihiro|Y|', 'Hiraka|Toshitada|T|', 'Kanoto|Masafumi|M|', 'Sato|Toshimitsu|T|', 'Tsunoda|Michihiko|M|', 'Ishizawa|Tetsuya|T|', 'Matsuda|Akiko|A|', 'Makino|Naohiko|N|']
D000328:Adult D000368:Aged D000369:Aged, 80 and over D001011:Aorta D003287:Contrast Media D005260:Female D006801:Humans D007091:Image Processing, Computer-Assisted D008297:Male D008875:Middle Aged D015588:Observer Variation D010179:Pancreas D010190:Pancreatic Neoplasms D055420:Perfusion Imaging D011829:Radiation Dosage D011832:Radiation Injuries D015203:Reproducibility of Results D059629:Signal-To-Noise Ratio D014057:Tomography, X-Ray Computed
Diagnostic imaging Broad clinical use Pancreatic cancer Single examination