Shozo Hirota MD, Presenter: Nothing to Disclose

Sachiko Achiwa MD, Abstract Co-Author: Nothing to Disclose

Satoshi Yamamoto, Abstract Co-Author: Nothing to Disclose

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

Hiroaki Maeda MD, Abstract Co-Author: Nothing to Disclose

Keisuke Arai MD, Abstract Co-Author: Nothing to Disclose

Reiichi Ishikura MD, Abstract Co-Author: Nothing to Disclose

Norio Nakao MD, Abstract Co-Author: Nothing to Disclose

et al, Abstract Co-Author: Nothing to Disclose

to evaluate usefulness of a cone-beam computed tomography (CBCT) system equipped with a flat panel detector (FPD) in detection of liver tumors comparing with contrast-enhanced MDCT.

1) CBCT: The indirect-type FPD provides a 40x30 cm FOV with cesium iodide (CsI) as the detector element, and pixel size of 194 micron. Data acquisition are 2048x1536x7.5 (fps) at imaging. Rotating range are 200｡ during 5 seconds. Voltage of X-ray tube are 100-110 Kvp. Images are reconstructed by the Feldkamp method. A cylindrical region measuring 235 mm in diameter and 176 mm in height allows reconstruction of all data obtained in a 180｡. The final reconstruction size is 512x512 pixels. 2) Clinical evaluation: CBCT angiography has been performed in 52 patients with liver tumors at our institution since September 2004 to January 2006. These studies were approved by IRB, informed consent was obtained from the patients in writing. These included 46 patients with hepatocellular carcinoma, 6 patients with liver metastases. CBCTAP (CBCT during arterial portography) was taken at delay time of 40 seconds after injection of contrast medium at a rate of 2 ml/s for 23 seconds. Intravenous contrast-enhanced triple phase CT using MDCT (Siemens; 4 or 16 detectors -raw) were performed within one month before interventional angiography. Imaging quality of CBCTAP was assessed clinically by three interventional radiologists comparing with that of contrast-enhanced MDCT, grading on a scale from 1(poor) through 3(equivalent) to 5 (excellent). Number of hepatic nodules detected by each of both CTs were counted, and compared with each other. And relative ratio of detected nodules by CBCTAP and IV contrast-enhanced CT (RD) of the same patient were evaluated.

1) Imaging quality: Average score of imaging quality was 2.72. 2) Nodules detected by CBCTAP were 258 and 211 by intravenous contrast-enhanced MDCT. A patient with numerous nodules was excluded. RD number is 1.424 on average.

CBCTAP detected hepatic nodules more than that by intravenous contrast-enhanced MDCT. CBCT images with an angiography system alone, saves space and time.

clinical study with new application

Hirota, S, Achiwa, S, Yamamoto, S, Kobayashi, K, Maeda, H, Arai, K, Ishikura, R, Nakao, N, et al, , Cone-beam CT with Flat-panel-detector Digital Angiography System: Detectability of Liver Tumors.  Radiological Society of North America 2006 Scientific Assembly and Annual Meeting, November 26 - December 1, 2006 ,Chicago IL. http://archive.rsna.org/2006/4432274.html