Noriaki Muraoka MD, Presenter: Nothing to Disclose

Hidemasa Uematsu MD, Abstract Co-Author: Nothing to Disclose

Hirohiko Kimura MD, PhD, Abstract Co-Author: Nothing to Disclose

Yoshiaki Imamura MD, PhD, Abstract Co-Author: Nothing to Disclose

Makoto Murakami MD, PhD, Abstract Co-Author: Nothing to Disclose

Harumi Itoh MD, Abstract Co-Author: Nothing to Disclose

We hypothesized that apparent diffusion coefficient (ADC) measurement could be useful to differentiate pancreatic cancer from normal pancreatic tissue. Our purpose was also to clarify the responsible component, which causes a diffusion abnormality in the cancerous tissue.

Thirty subjects (21 men and 9 women, mean age: 68years) with pancreatic cancer were recruited. Fourteen cases were surgically confirmed as pancreatic cancer. The other 16 cases were clinically confirmed based on imaging findings and serological tumor markers. A single-shot EPI-DWI technique (b=0 and 500 s/mm2) was employed to produce an ADC map. ADC values were compared between the tumor and normal-appearing parenchyma using the Wilcoxon matched-pairs test, in which a p-value of less than 0.05 was considered statistically significant. Furthermore, we also compared ADC value of the cancer with pathological findings in the 9 subjects who underwent tumor resection.

In all 30 cases, signal intensity on DWI was higher for the tumor than for normal-appearing pancreatic tissue. The mean ADC value of the tumor (1.34±0.32×10-3 mm2/s) was significantly lower than that of normal-appearing pancreatic tissue (1.64±0.39×10-3mm2/s, P<0.0001). Regarding correlation between ADC and histopathological features in the 9 surgically resected cases, 6 cases exhibited lower ADC values in the cancerous area than in normal-appearing parenchyma. In these 6 cases, histopathological examination showed dense collagenous fibers was prevailing compared with cellular component, coagulation necrosis, and mucin. In remaining 3 subjects, ADC value of the cancerous area was higher than that of normal-appearing parenchyma. Histopathological examination showed loose collagen fibers were prevailing rather than cellular component, and mucin.

ADC values for tumors were lower compared to normal-appearing pancreas tissue. The pathological features of the tumor appear to affect the ADC value.

ADC value may be useful in differentiating pancreatic cancer from normal appearing pancreas tissues.

Muraoka, N, Uematsu, H, Kimura, H, Imamura, Y, Murakami, M, Itoh, H, Apparent Diffusion Coefficient in a Pancreatic Cancer: Characterization and Histopathological Correlation.  Radiological Society of North America 2007 Scientific Assembly and Annual Meeting, November 25 - November 30, 2007 ,Chicago IL. http://archive.rsna.org/2007/5009838.html