Diagnostic Radiology
Introduction
The Division of Diagnostic Radiology is committed to improving health through excellence in image oriented patient care and research. Furthermore our Division performs more than 62,000 inpatient and outpatient procedures annually. Our division also conducts clinical scientific research as well as basic scientific research. Such breakthrough research achievements translate directly into better patient care.
Routine Activities
Diagnostic Modalities
Our Division has three helical CT scanners, two 1.5T MRI systems, two digital subtraction angiographic (DSA) systems, two gamma cameras with the capacity for single photon emission CT (SPECT), two digital radiographic (DR) systems for fluoroscopy, two mammography and four computed radiographic (CR) systems. One DSA system is equipped with helical CT, and is also referred to as an IVR-CT system. These all-digital image systems enhance the efficacy of routine examinations.
Services
Our Division includes five consulting radiologists and thirteen technologists. As our routine work, every effort is made to produce an integrated report covering all examinations, such as plain radiographic examinations (chest, abdomen, head, neck, breast, bone and other structures), contrast radiological procedures (digestive, urinary and respiratory tracts), CT, MRI, RI, angiography and interventional radiology (IVR), mainly transarterial embolization (TAE). The number of cases examined in 1998 is shown in the Table. In addition, several conferences (teleradiologic, pre- and postoperative) have been held in our Division.
Research Activities
Our Division has been developing a system of helical CT with the support of the Comprehensive 10-year Strategy for Cancer Control and the new 10-year Strategy for Cancer Control. The prospective study of helical CT guided subsegmental TAE for the treatment of hepatocellular carcinoma is ongoing. Helical CT is also applicable to screening of lung cancers. A feasibility study is now ongoing in cooperation with the thoracic oncology groups at the National Cancer Center Hospital (NCCH) and the Anti-Lung Cancer Association.
Using an exclusive optical fiber line between the Tsukiji and Kashiwa campuses, regular and optional image conferences have been held. By extension of this network, these conferences have been opened to other cancer centers, as well as other national hospitals.
By using the recent advancement of computer graphics, our Division has achieved great success in obtaining three-dimensional displays of the internal body, based on imaging data from helical CT and MRI. This is useful for planning surgery or radiotherapy, for doctors training and for patient education.
A computer-aided diagnosis (CAD) system for breast cancer using FCR (Fuji Computed Radiography) mammograms is being developed. In 4,148 digital mammograms including 267 cases of breast cancer, the sensitivities to breast cancerous tumors and clustered microcalcifications were 90% and 93%, respectively. Their false-positive rates were 1.37 and 0.40 per image, respectively. Observer performance studies indicate that an average Az value for the five doctors was greater with the CAD system than by film-only reading without CAD, and that reading with CAD was significantly superior at P ＜ 0.022.
Also another CAD system for lung cancer using CT images and for brain tumors using MRI images is being developed. These CAD systems promise to have a great influence on cancer diagnosis as well as on patient care in the near future.
New Developments
1. One helical CT was updated. Its large heat unit X-ray tube (6.5MHU) makes possible clear thin slice (2-3 mm) CT images in patients with bile duct cancer.
2. One clinical laboratory technician was assigned to our MRI group from NCCH. We have been able to use two MRI units three days per week through his help.
3. We started stereotactically guided core needle biopsy using mammography for unpalpable breast lesions that were only detected by mammography.
4. Our interventional radiology group developed new methods for gastrostomy under CT fluoroscopy in patients with upper esophageal cancer or head and neck cancer who could not take food or drink from mouth.
Statistics
| Plain X-ray examination | 37,461 |
| Mammography | 1,230 |
| Fluorography (GI-series, etc.) | 3,380 |
| CT | 13,994 |
| MRI | 3,095 |
| RI | 2,172 |
| Angiography | 743 |
| Total | 6,2075 |
(S. Nawano)
