Imaging study of pancreatic ductal adenocarcinomas in Syrian hamsters using X‐ray micro‐computed tomography (CT)

Abstract

X-ray computed tomography (CT) has been used for diagnoses of human pancreatic cancer. Although micro-CT is a useful approach to evaluate macromorphology of organs ⁄ tissue also in animal models, reports on pancreatic tumors are limited. In this study, the utility of micro-CT was assessed in characterizing chemically induced pancreatic tumors in Syrian hamsters. Hamsters treated with or without N-nitrosobis(2-oxopropyl)amine (BOP) were injected with the antispasmodic agent, scopolamine butylbromide, and contrast agents, 5 or 10 mL ⁄ kg body weight of iopamidol or Fenestra VC at 18-38 weeks, then examined by micro-CT scanning with a respiratory gating system. Both peristaltic and respiratory movements were substantially suppressed by the combination of scopolamine butylbromide treatment and the respiratory gating system, resulting in improvements of image qualities. Iopamidol clearly visualized the pancreatic parenchyma and contrasted the margins among the pancreas and other abdominal organs ⁄ tissue. Meanwhile Fenestra VC predominantly contrasted abdominal vascular systems, but the margins among pancreas and other organs ⁄ tissue remained obscure. Six pancreatic tumors of 4-13 mm in diameter were detected in four of 15 animals, but not the five tumors of 1-4 mm in diameter. The inner tumor images were heterogeneously or uniformly visualized by iopamidol and Fenestra VC. Overall, iopamidol could clearly contrast between pancreatic parenchyma and the tumors as compared with Fenestra VC. All tumors confirmed were histopathologically diagnosed as pancreatic ductal adenocarcinomas. Thus, micro-CT could be useful to evaluate the carcinogenic processes and preventive methods of pancreatic cancer in hamsters and to assess the novel contrast agents for detection of small pancreatic cancer in humans. (Cancer Sci 2010; 101: 1761-1766 P ancreatic cancer is the fifth cause of cancer death in Japan and ranks high in mortality among developed countries. (1,2) Because of the difficulty in detecting pancreatic cancer in early operable stages, and because of the lack of any curative treatment approaches other than complete surgical removal, 5-year relative survival rate is <6%.(3,4) Therefore, for improvement of outcome, future strategies for early diagnosis of pancreatic cancer should aim at diagnosing most pancreatic cancers before they grow 20 mm in size. (5,6) X-ray computed tomography (CT) has been widely used in detection and evaluation of pancreatic tumor progression and metastasis during clinical treatment. Recently, the CT devices have been markedly improved in their volume coverage speed, longitudinal resolution, and quality of three-dimensional reformations. In addition, dynamic CT scanning has been developed, in which CT-images of pancreas can be obtained for a short time with breath holding. This method reveals some adequate contrasts between pancreatic parenchyma and neoplastic lesions. However, detectability of small pancreatic cancer, especially those <10 mm in size, has not yet been satisfactory.(8-10) Further a...

In vivo 18F-fluorodeoxyglucose-positron emission tomography/computed tomography imaging of pancreatic tumors in a transgenic rat model carrying the human KRASG12V oncogene

“…Using this technique, studies may be able to control the size of the pancreatic tumor quantitatively within an appropriate time period, a factor that demonstrates the usefulness of this model. With regard to studies that have used small animal models, Kitahashi et al (21) used micro-CT to detect chemically-induced pancreatic tumors of >4 mm in diameter in Syrian hamsters. Another study by Fendrich et al (18) detected precursor pancreatic adenocarcinoma lesions with an activity of 9.6±0.5 MBq in a five-month-old transgenic mouse model by FDG-PET/CT.…”

Diagnostic Yield of Micro-Computed Tomography (micro-CT) Versus Histopathology of a Canine Oral Fibrosarcoma

“…11 In veterinary medicine, micro-CT has become a valuable in vitro tool for biological research as well as clinical diagnostics [12][13][14][15][16][17] and has proven to be beneficial as an in vivo diagnostic technique to visualize anatomical alterations as small as 30 mm in rodents and rabbits. 2,[18][19][20][21][22] Studies indicated that highresolution micro-CT can complement, if not replace, histopathology as the state-of-the-art standard in in vitro research and may become a viable part of in vivo clinical diagnostics. 2 The aim of the present case report was to determine the diagnostic yield of ex vivo micro-CT in a histopathologically confirmed canine oral fibrosarcoma that was removed by means of partial maxillectomy.…”

Analysis of the microvascular morphology and hemodynamics of breast cancer in mice using SPring-8 synchrotron radiation microangiography

“…The resolution of ultrasound and contrast-enhanced magnetic resonance images (CE-MRI) are reported to be about around 100-200 mm. Micro-computed tomography (CT) and micro-MRI provide higher resolutions (< 50 mm), three-dimensional images and quantitative evaluation of angiogenesis, but a serious limitation is the limited ability for real-time analysis of blood flow dynamics (Savai et al, 2009;Kitahashi et al, 2010;Missbach-Guentner et al, 2011;Geffre et al, 2015). SR microangiography is potentially useful to assess and quantify intratumoral blood vessel morphology and blood flow dynamics in vivo more precisely, and with high resolution, spanning several centimeters visualization depth.…”