Diagnostic Radiology Division

Introduction
The Diagnostic Radiology Division comprises of four groups, divided according to their area of concentration into the gastrointestinal tract group, the hepatobiliary and pancreas group, the nuclear medicine　group, and the chest group. Over 107500 inpatient and outpatient radiographic procedures were performed in2001. In our division, the major activities are to make a diagnosis for patients with malignant tumors using several imaging modalities and to develop new imaging techniques to improve the quality of diagnostic images.Now, our division has five helical computed tomography (CT) systems, two 1.5T magnetic resonance imaging(MRI) systems, two digital subtraction angiographic (DSA) systems, three gamma-cameras, three digital radiographic (DR) systems for gastrointestinal examinations, and two mammographic systems. One DSA system is equipped with a helical CT and is referred to as an IVR-CT system. All medical images in our new hospital are digitized. Original or compression images of computed radiography (CR), digital radiography (DR),radioisotope (RI), CT, and MRI can be easily and rapidly retrieved from the medical information system for research, administration, and clinical expertise (MIRACLE).

Routine Activities　
1. Gastrointestinal Tract Group: Two radiologists are at work to examine patients with gastrointestinal (GI) tract cancers, such as gastric, esophageal and colon cancers. In addition, drip infusion pyelography (DIP) and mammography are also practiced by one of them. The number of the GI examinations came up to 2400 in 2001,and more than half of them were close examinations for surgical operation. Many early-stage lesions were investigated by the double contrast method, and all the studied were performed with newly developed digital radiography (DR).
2. Hepatobiliary and Pancreas Group: Five radiologists belong to this group, which performs integrated diagnostic imaging using CT, MRI, angiography, and IVR-CT for diagnosing cancer in parenchymatous organs, including the liver, pancreas, kidney, spleen, ovary, uterus, and brain. Over 21100 CT examinations, over 5300 MRI examinations, and 489 angiographic examinations were performed.We are actively involved in performing interventional radiology, especially therapeutic arterial embolization combined with chemotherapy and fluoro-CT guided percutaneous ethanol injection (PEI) for treatment of hepatocellular carcinoma (HCC).
3. Nuclear Medicine Group: There are two nuclear physicians and two nuclear technologists in this group, which has three gamma cameras. However, PET scanner is not available yet. They are treating over 3,200 patients annually. Of these examinations, 75% are whole body bone scans, 15% are Ga-67 scans, and 1% are Tl-201 scans for malignant bone and soft tissue tumors. In the last five years, emergency Tc-MAA lung scan for the post-surgical pulmonary embolism cases are increasing.
4. Chest Group: One radiologist and two doctors from another division belong to this group, which carried out over 46,000 chest radiographies and 15,000 chest CT. Helical CT examination is routinely used for the detection and the evaluation of lung tumors and various pulmonary abnormalities in addition to routine chest radiography. High-resolution CT is performed in the diagnosis of small peripheral lung cancers and other subtle abnormalities. Additionally, in order to obtain cytopathological diagnosis, fluoro-CT guided percutaneous needle biopsies for intrathoracic mass were performed in the more than 100 cases in 2001.
5. Conferences: There are several conferences with other divisions, including preoperative gastric conferences, hepato-biliary and pancreas conferences, breast conferences, chest conferences etc; some of the conferences are held as remote TV conferences.

Research Activities
This division has been developing medical imaging instruments with the support of the new Ten-year Strategy for Cancer Control. Methodology of CT examination using a multi-detector-CT has been under review. A computer-aided diagnosis (CAD) system for both breast cancer using Fuji Computed Radiography (FCR)mammograms and lung cancer using a helical CT has been more developed. Digitalization of medical images in GI examinations was achieved by digital radiography using 4 million pixel CCD, and newly developed DRsystem with flat panel detector has been put into practice for clinical evaluation. Two studies to confirm the diagnostic accuracy using video-monitor system and to clarify problems of the subjects for future CRT diagnosis were conducted. Moreover, GI reporting and referential image data system has been developed. In hepato-biliary and pancreas group, three-dimensional displays of several organs with neoplasms based on CT and MR imaging data are used in planning treatment. Overall survival rates of transarterial chemoembolization (TAE) for patients with inoperable hepatocellular carcinoma (HCC) are evaluated during five years after installation of a unified CT and angiography system. Whereas, the natural course of early hepatocellular carcinoma and adenomatous hyperplasia diagnosed by dynamic CT is followed up and assessed. In the study of CT during arterial portography (CTAP) for the preoperative evaluation of liver metastases from pancreatic carcinoma, both CTAP and intravenous contrast-enhanced CT (IVCT) showed the same diagnostic accuracy. Therefore, CTAP did not confer any advantage over IVCT for the preoperative assessment of liver metastases from pancreatic carcinoma (Frukawa).

New Developments
1. GI group is developing new DR system with flat panel detector, CRT diagnosis and reporting system for GIstudies. These projects have just started under joint researches with medical imaging companies
2. New CAD system has been put into practice for clinical evaluation in the detection of breast cancer and lungcancer.
3. Multi-detector CT has been put into practice for clinical evaluation in the diagnosis of HCC, bile duct cancer, pancreas cancer, breast cancer and lung cancer.
4. Clinical stages based on imaging diagnosis in HCC and pancreas cancer has been evaluated. This new clinicalstage is expected to be useful in the selection of medical treatments.
5. Several new imaging methods, including functional imaging, diffusion imaging, MR-angiography (MRA),and MR-cholangiopancreatography (MRCP) are routinely used. Using these methods, we can obtain new information about tumors and other abnormalities. New surface coil for pancreas has been under review in MRI.
6. Original or compressed images of CR, DR, RI, CT, and MRI can be easily and rapidly referenced on the medical information system for research, administration, and clinical expertise (MIRACLE) during past 5 years. Some chest X-ray and MRI reports are made by using this system.

Y. MURAMATSU

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