Ichiro Yamada MD, Presenter: Nothing to Disclose

Keigo Hikishima PhD, MS, Abstract Co-Author: Nothing to Disclose

Naoyuki Miyasaka MD, Abstract Co-Author: Nothing to Disclose

Keiji Kato MD, Abstract Co-Author: Nothing to Disclose

Eisaku Ito MD, Abstract Co-Author: Nothing to Disclose

Kazuyuki Kojima MD, PhD, Abstract Co-Author: Nothing to Disclose

Tatsuyuki Kawano MD, Abstract Co-Author: Nothing to Disclose

Daisuke Kobayashi MD, Abstract Co-Author: Nothing to Disclose

Yoshinobu Eishi MD, Abstract Co-Author: Nothing to Disclose

Hideyuki Okano MD, PhD, Abstract Co-Author: Nothing to Disclose

To determine the feasibility of non-Gaussian q-space diffusion-weighted MR imaging as means of evaluating mural invasion by gastric carcinomas and the histologic grades of gastric carcinomas.

Twenty gastric specimens each containing a carcinoma were studied with a 7.0-T MR imaging system equipped with a four-channel phased-array surface coil. q-Space diffusion-weighted MR images were obtained with repetition time, 3000 msec; echo time, 29 msec; field of view, 50-60 mm x 25-30 mm; matrix, 256 x 128; section thickness, 2 mm without intersection gaps; ten b values ranging from 0 to 7163 sec/mm2; and motion-probing gradient in the y-direction. Three q-space imaging parameters (mean displacement, probability for zero displacement, and kurtosis) were calculated from the displacement distribution profiles, and standard apparent diffusion coefficient (ADC) was also calculated from two b values (b = 0 and 874 sec/mm2). The MR images were then compared with the histopathologic findings as the reference standard.

In all 20 specimens (100%), q-space imaging parameter maps were capable of depicting the individual layers of the normal gastric wall. The q-space imaging parameter maps in all 20 carcinomas (100%) made it possible to identify the same depth of tumor invasion of the gastric wall as observed during the histopathologic examination. The mean displacement (5.78 ± 0.36 µm), probability for zero displacement (52.6 ± 4.2 (arbitrary unit [a.u.])), and kurtosis (55.1 ± 5.1 (a.u.)) of the carcinomas were statistically significantly different from the corresponding values of the layers of the gastric wall. The mean displacement (r = -0.841; P = 0.001), probability for zero displacement (r = 0.927; P < 0.001), and kurtosis (r = 0.927; P < 0.001) were statistically significantly correlated with the histologic grades of gastric carcinomas, while the ADC (r = -0.341; P = 0.255) showed no significant correlation with the histologic grades of gastric carcinomas.

q-Space diffusion-weighted MR imaging is feasible in gastric specimens and provides excellent diagnostic accuracy for evaluating mural invasion by gastric carcinomas and the histologic grades of gastric carcinomas.

q-Space diffusion-weighted MR imaging may provide a diagnostic tool for noninvasive assessment of mural invasion by gastric carcinomas and the histologic grades of gastric carcinomas.

Yamada, I, Hikishima, K, Miyasaka, N, Kato, K, Ito, E, Kojima, K, Kawano, T, Kobayashi, D, Eishi, Y, Okano, H, q-Space Diffusion-weighted MR Imaging of Gastric Carcinoma Ex Vivo: Correlation with Histopathologic Findings.  Radiological Society of North America 2014 Scientific Assembly and Annual Meeting, - ,Chicago IL. http://archive.rsna.org/2014/14007235.html