PubMed Health⌕ Search

Biomedical subjects

Tokiko Endo

Publications and source records attributed to Tokiko Endo.

12 recordsLinked to original sources

Evaluation of new image processing conditions for digital mammograms from Fuji computed radiography.

PURPOSE: A new processing parameter (T-type parameter) setting for gray scale was developed to improve the image quality of digital mammograms. To clarify the usefulness of this parameter setting, we have evaluated the image quality of digital mammograms (hard copy images) processed with this parameter, and compared it with S/F mammography. MATERIAL AND METHODS: Mammograms were made under the same radiographic conditions by the S/F and FCR systems (type 1, S/F; type 2 and 3, FCR with new T-type parameters; type 4 and 5, FCR with conventional parameters). A total of 49 images from 10 cases was selected for evaluation testing. Evaluation items were the contrast visibility of mammary glands and adipose tissues together with their granularity and sharpness. Eleven medical doctors participated in evaluating the images. RESULTS: The FCR hard copy images processed with the T-type parameter settings were significantly preferred over the conventional S/F images for the contrast visibility of mammary glands and adipose tissue. As for the other items (except for granularity), the FCR hard copy images processed with the T-type parameter settings were subjectively evaluated as slightly better than or equal to the S/F images. In contrast, the conventional S/F images were significantly preferred over the FCR hard copy images processed with the conventional parameter settings. CONCLUSION: The image quality of FCR hard copy images processed with the T-type parameter settings was preferred over that of conventional S/F images as evaluated by medical doctors who specialized in mammography interpretation.

Female↗

Current status and goals of mammographic screening for breast cancer in Japan.

In Europe and the United States, the proportion of women receiving mammographic screening for breast cancer has increased to 60-80%, resulting in an increase in the detection of early-stage cancer and a reduction in the mortality rate. The objectives of breast cancer screening have thus already been achieved there. In Japan, both the incidence and mortality of breast cancer have increased recently. Breast cancer screening has long been performed by clinical breast examination (CBE) alone. A reduction in the mortality of breast cancer cannot be expected from CBE. Mammographic screening for breast cancer was recommended in a notification issued by Ministry of Health, Labour and Welfare in 1999. An important aspect of mammographic screening is quality control. The Central Committee on Quality Control of Mammographic Screening(Central Committee)was organized by six screening-related societies, and attempts have since been made to establish a quality control system. Both the social recognition of the Central Committee and its cooperation with the "Quality Control Committee " of each community will become important. The cover rate of nationwide breast cancer screening by CBE alone is 12-13%, while the implementation rate of mammographic screening is presently very low and its cover rate is considered to be about 2%. With such a low cover rate, it is absolutely impossible to reduce the mortality of breast cancer. To achieve this, the administration and clinicians will be required to cooperate with each other to increase the spread and cover rate of high-quality mammographic screening.

Breast Neoplasms↗

[Breast cancer screening in Japan--present status and recent movement].

As the incidence of breast cancer and deaths from breast cancer have been increasing, the Ministry of Public Welfare and Labor has been promoting breast cancer screening. Mammography screening began in fiscal year 2000 for those women 50 years of age or over, but attendance has not been increasing. This year (2004), the Ministry determined that mammography would be applicable to those 40 years of age or over and that screening with palpation alone would be abolished. To determine the effectiveness of the measures, mammography equipment, technologists, and readers were calculated. If the attendance were 50% of the 35,497 thousand women in this biennial screening, 40 persons would be examined by one apparatus per day, and, as there are 200 working days in a year, 1,109 apparatus would be needed. In the same way, if a technologist can examine 5,000 women, and a doctor can read 10,000 cases a year, both are apparently deficient in some prefectures. The standards of quality control for digital mammography have been determined by the Japan Radiological Society, and a "step phantom for mammography" has been developed. Qualitative evaluation of hard-copy clinical images has also started. All of the standards are presented in "Mammography Guidelines, Second Edition," published by Igakushoin, Tokyo, Japan, 2004.

Adult↗

[Mammography].

Explore the source record for details and available documents.

Breast↗

The role of contrast-enhanced MR mammography for determining candidates for breast conservation surgery.

PURPOSE: The aim of this study was to assess the impact of preoperative magnetic resonance mammography (MRM) on the surgical determination of breast conservation treatment for breast cancer patients. METHODS: From September 1997 to March 2000, 57 consecutive breast conservation treatment candidates were prospectively evaluated with conventional imaging studies (mammography and ultrasonography) and preoperative MRM. RESULTS: In 47 of 54 (87% ) breast cancer patients breast conservation surgery (BCS) was indicated on the basis of mammography (MMG) and ultrasonography (US). However in 40 of the 54 (74% ) patients BCS was indicated on the basis of MRM. Thirty-eight of the 40 patients ultimately underwent BCS and only 1 showed a positive margin. There were 7 patients whose MRM findings suggested that more aggressive treatment than BCS was needed but for whom US/MMG suggested that BCS was appropriate. Five of the 7 patients underwent mastectomy rather than BCS based on the MRM findings, which were justified by post-surgical histological findings. Of the 2 remaining patients who underwent BCS, one had a positive histological margin and one had recurrence, both of which resulted in salvage mastectomy. CONCLUSION: Our study suggests that high resolution preoperative MRM provides more accurate information compared with US and MMG for selecting candidates for BCS. Using MRM as a routine staging tool may reduce unnecessary repeated excisions. A larger study will be required to confirm these findings and to define the patients most likely to benefit from breast MR imaging.

Adult↗

[A comparison between physicians' interpretation and a CAD system's cancer detection by using a mammogram database in a physicians' self-learning course].

We have been developing automated detection algorithms for masses and clustered microcalcifications in a mammography computer-aided diagnosis (CAD) system. In this study, we investigated the potential of our CAD system by comparing 579 physicians' interpretation results with that of the CAD system's cancer detection for 100 mammograms (21 malignant and 29 benign cases) employed in a physicians' self-learning course. As a result, our CAD system detected 7 out of 8 malignant lesions whose physicians' averaged sensitivity was less than 60%. Although the average of physicians' sensitivities were 76% (about 16 cases), the CAD system's detection rate was 90% (19 cases). Sensitivity was raised up to 97% if the physicians' interpretation and the CAD system's detection result were treated in a matter of logical OR. Thus, it was raised the possibility that even the less-experienced physicians would diagnose with a higher sensitivity by using the computer output as a guide effectively.

Breast Neoplasms↗

[Considerations in breast imaging diagnosis].

Certain points regarding breast imaging diagnosis are open to interpretation and are considered difficult to understand in the short course on mammography. For example, focal asymmetric density (FAD) may or may not include mass lesions. To assess whether FAD includes mass lesions or not, a comparison of density with equal gland volume, margins, and internal structure is important. Calcifications must be read carefully according to shape and distribution. The shapes of calcifications can be used to estimate the intra-ductal structure of breast cancer, but small round calcifications and amorphous calcifications can be interpreted as both benign and malignant lesions. Therefore, distribution brings important information to the assessment. Architectural distortion can be caused by fibrosis in both benign and malignant lesions. Lobular carcinoma and scirrhous carcinoma are the most common malignant diseases, but radial scar, inflammatory disease, and surgical scar need to be considered in the differential diagnosis. Finally, the pathological assessment of breast cancer and mammographic technology are basic, important factors in reading mammography.

Breast↗

[X-ray phase imaging using a X-ray tube with a small focal spot -improvement of image quality in mammography-].

Phase contrast X-ray imaging has been studied intensively using X-rays from synchrotron radiation and micro-focus X-ray tubes. However, these studies have revealed the difficulty of this technique's application to practical medical imaging. We have created a phase contrast imaging technique using a molybdenum X-ray tube with a small focal spot size for mammography. We identified the radiographic conditions in phase contrast magnification mammography with a screen-film system, where edge effect due to phase contrast overcomes geometrical unsharpness caused by the 0.1mm-focal spot of a molybdenum X-ray tube. The edge enhancement due to phase imaging was observed in an image of a plastic tube, and then geometrical configuration of the X-ray tube, the object and the screen-film system was determined for phase imaging of mammography. In order to investigate a potential for medical application of this method, we conducted evaluation of the images of ACR 156 mammography phantom. We obtained higher scores for phase imaging using high speed screen-film systems without any increase of X-ray dose than the score for contact imaging using a standard speed screen-film system.

Female↗

Pancreatic ductal adenocarcinoma showing iso-attenuation in early-phase contrast-enhanced CT: comparison with histopathological findings.

PURPOSE: To clarify the CT characteristics and histopathological findings of pancreatic ductal adenocarcinomas that are not detected in early-phase contrast-enhanced CT images. MATERIALS AND METHODS: The CT findings of eight patients with histopathologically proven pancreatic carcinomas that were not detected in early-phase images following the rapid injection of contrast material were reviewed. The examinations consisted of pre-contrast-enhanced CT and multi-phase contrast-enhanced CT, with thin-section scanning in each patient. The CT findings were compared with those of the resected specimens. RESULTS: In all cases but one, the lesion was in the pancreatic head. In seven cases, the tumor did not appear as a focal area of hypoattenuation compared with surrounding pancreatic parenchyma in early-phase images, and in the remaining case, small areas of poor enhancement were observed. In late-phase images, hyperattenuated and isoattenuated areas were seen in six and two cases, respectively. In all but one case, the lesion was less than 40 mm in size. All lesions were composed of acinar tissues and tumor cells, and contained small amounts of mucin, necrotic tissue, and pus. The fibrous tissues were not abundant and were interlobular and/or relatively loose. CONCLUSION: Pancreatic ductal adenocarcinomas showing isoattenuation in early-phase images tend to be relatively mild lesions with scirrhous and/or desmoplastic changes.

Adenocarcinoma↗