Monitoring of domestic and imported apples and rice by the U.S. Food and Drug Administration pesticide program.

In 1993-94, the U.S. Food and Drug Administration (FDA) conducted a statistically based study of pesticide residues in domestic and imported fresh apples and processed rice. For apples, 769 domestic and 1062 imported samples were collected and analyzed; 85% of the domestic and 86% of the imported samples had detectable residues. Benomyl, a widely used fungicide, was found with greatest frequency in domestic apples, while diphenylamine was found most often in imported apples. One domestic and 4 imported samples contained violative residues of pesticides for which there are no U.S. tolerances on apples. The statistically weighted (by domestic packer throughput or import shipment size) violation rates for domestic and imported apples were 0.30% (0.13 unweighted) and 0.41% (0.38 unweighted), respectively. For rice, 598 domestic and 612 imported samples were collected and analyzed; 56% of the domestic and 12% of the imported samples had detectable residues. Malathion had the greatest frequency of occurrence in both groups of rice. Eight domestic and 9 imported samples were violative, all as a result of use of pesticides for which there are no U.S. tolerances on rice. The statistically weighted violation rates for domestic and imported rice were 0.43% (1.3 unweighted) and 1.1% (1.5 unweighted), respectively. Results of the statistically based study show that, as in FDA's regulatory monitoring, the levels of most pesticide residues found in these 2 commodities are generally well below U.S. tolerances, and few violative residues are found.

[Use of the ROC method in problems of image quality and quality control in mammography]. / Anwendung der ROC-Methode auf Probleme der Bildgüte und Qualitätskontrolle in der Mammographie.

The ROC method is being used increasingly in radiology for the purpose of checking image quality. A phantom has been developed for use in mammography, which takes account of the tissues of the breast and of abnormal changes. In order to compare image quality, various films and film-screen systems were employed. The effect of slice-thickness, focal spot size and radiation scatter on image quality has been examined. The suitability of the method for quality control has been tested on a small sample. In addition, certain important parameters of the radiographic technique have been determined by physical measurements. Certain methodological difficulties must be considered, eg. the problem of statistical significance. It has been shown, however, that film-screen systems can approach the image quality of screenless films and require a lower dose of x-rays. For larger slice thickness, the use of a grid produces significantly better results than film without screens alone. The findings of the quality control show that it is important to check image quality by means of physical measurements. The ROC method has proved less valuable in this respect.

[Studies about the exposure to radiation of the fetus in case of X-ray examination during gravidity (author's transl)]. / Untersuchungen zur Strahlenexposition der Leibesfrucht bei Röntgenuntersuchungen während der Schwangerschaft. 3. Mitteilung: Abschätzung der Strahlenexposition aus der Empfindlichkeit des bildgebenden Systems.

In the second communication (Strahlentherapie 156 (1980), 776-785), we discussed the estimation of the exposure to radiation of the fetus by means of tube related data (product of area/surface dose or time/tube current). In this final communication, we present method and problems of the estimation based on the sensitivity of the picture-producing system. In order to apply this method, one must know several factors characterizing the attenuation of X-radiation between the point of incidence and the picture carrier. A detailed report is given on the results of measurements effected on a water phantom in order to find out these factors of attenuation. Then the estimated surface doses are compared to the values determined by thermoluminescence dosimetry. We come to the conclusion that the estimation of the exposure to radiation by means of tube related data will generally involve a lower deviation from the actual value than the estimation based on the dose required by the receiving system.

[Investigation of the exposure to radiation of the embryo in the course of x-ray examination during pregnancy. 2nd communication: Estimation of the exposure to radiation using the area-dose or the tube-current-time product (author's transl)]. / Untersuchungen zur Strahlenexposition der Leibesfrucht bei Röntgenuntersuchungen während der Schwangerschaft. 2. Mitteilung: Abschätzung der Strahlenexposition aus dem Flächendosis- oder Röhrenstrom-Zeit-Produkt.

Thermoluminescence dosimetry of surface doses and doses near the uterus was performed during standardized X-ray examinations of the pelvis. Surface doses and the dose to the uterus were estimated from the available radiographic data referred to the tube and with the use of tissue/air ratios, and a comparison with the results of measurement was made. This comparison shows that the mean whole-body dose to the embryo can be estimated with a relative total risk of 20%, if all essential data of the exposure to radiation are present and if the position in depth of the embryo is known. Guiding data of the surface dose and of the dose to the uterus are given individually for fluoroscopic tests, a.-p. and lateral radiographs under standardized conditions of X-ray examination.

[The importance of mammography in relationship to the number of treated carcinomas of the breast. Partial results from 1976--1978 of a long term study (author's transl)]. / Bedeutung der Mammographie bezogen auf die Zahl aehandelter Karzinome. Teilergebnisse (1976--1978) einer langfristigen Studied.

From 1976 to 1978 11, 197 women were examined clinically and mammographically. Biopsy material from 1,673 breasts were examined microscopically. In 536 cases, or almost every third case (32%), a carcinoma of the breast was detected. The cancer was bilateral in 19 cases and the total number of women was therefore 517. A clinically occult tumour was only found in 7.7% (40 of 517) of the cases. 5% of these patients were high risk patients and 2.7% preventive examinations. 5 women with occult carcinoma of the breast were under age 40 and 14 under age 50. Benign changes of the glandular tissue were found in 59.5% of the cases. Marked proliferative changes were found in 4.6% of the cases and carcinoma in situ was found in 3.8% of the patients. In the age group 45--54 benign and proliferative changes of the parenchyma occured almost twice as often as cancers. The ratio between benign and malignant findings was 1:1 in the age group 55--59 and was less than 1:2 in the age group over 70. A sophistication of the mammograhic technique must be obtained. A thorough microscopic examination of tissue from subcutaneous mastectomies and tissue obtained at the time of reduction mammoplasties showed occasionally unexpected malignant tissue in an unexpected location. Especially these cases are suitable for later comparison to the mammographies.

[Investigation of the exposure to radiation of the embryo/fetus in the course of radiographic examinations during pregnancy 1st communication: Tissue-air ratios for X-rays with tube voltages between 60 kV and 120 kV (author's transl)]. / Untersuchungen zur Strahlenexposition der Leibesfrucht bei Röntgenuntersuchungen während der Schwangerschaft. 1. Mitteilung: Gewebe-Luft-Verhältnisse für Röntgenstrahlen mit Röhrenspannungen zwischen 60 kV und 120 kV.

A relatively important radiation dose delivered to the embryo (fetus) is a decisive criterion, if interruption of pregnancy is considered for radiation-hygienic reasons. Several methods of assessment by calculation of the fetal exposition are discussed; in the last analysis, there are always needed the values of the relative depth doses or tissue-air ratios. The tissue-air ratios for the diagnostical X-ray qualities from 60 to 120 kV (total filtration 2.6 mm Al) were ascertained with the help of a water phantom. They are represented for layers from 0 to 20 cm by means of tables, and a comparison is made with data from the literature.

[Image quality in film and xero mammography. Second paper. Reproduction of medium range contrast (author's transl)]. / Untersuchungen zur Bildgüte bei der Film- und Xeromammographie. 2. Mitteilung: Wiedergabe mittlerer Strahlenkontraste.

In our first paper we dealt with the reproduction of low contrast ranges during the radiological examination of the breast. In the present paper we are concerned with medium contrast ranges, using a semi-objective procedure. This again depended on visual evaluation of test films of grids with variable grid ratios. For mammography rotating molybdenum and tungsten tubes with various filters were available. The advantages of xere radiography in rendering detail were less marked in these medium contrast ranges. The disadvantage of scatter is again less marked, but the resolution of non screen film for small and medium-sized objects is considerably greater. However, xero-radiography, using a tungsten tube with 0.5 mm. Al. filtration represents a satisfactory compromise between image quality and radiation dose for the demonstration of small and medium contrast ranges.

Early detection of ductal breast cancer: the diagnostic procedure for grouped microcalcifications.

Mammography and xeroradiography for grouped microcalcifications are considered the most effective diagnostic methods to detect occult breast carcinoma. Radiography must direct the surgeon to excise the nonpalpable area. The removal of the tissue with grouped microcalcifications must be confirmed by intraoperative radiological control. The histologic preparation must be guided by radiographic controls. Tissue with calcific deposits is examined by step sections. The diagnostic success depends upon the cooperation between the radiologist, the surgeon, and the pathologist. Our results from 1964 to 1977 have shown a frequency of 14.4% of occult carcinoma. Ductal or lobular carcinomata in situ have been diagnosed in 8.9%. In 9.9% of the patients, cystic disease with severe and atypical proliferations has been encountered.

Early detection of ductal breast cancer: the diagnostic procedure for pathological discharge from the nipple.

Pathologic discharge from the nipple may be the only symptom of an early stage of carcinoma. Galactography is then the diagnostic method of choice to locate intraductal, nonpalpable lesions. The technique of galactography, the adequate surgical approach of pathologic galactographs (milk-duct segment resection), and the appropriate histological work-up of the surgical specimen are demonstrated. We report on 1918 galactographies in 1363 women with pathological discharge. In only 427 cases was a milk duct segment resection necessary (31.4%). In 8.5%, we found invasive intraductal cancer and in 2.9% ductal carcinomata in situ. Only 1 patient with breast cancer had axillary metastases. Extensive intraductal solid, papillary or adenomatous proliferations were found in 11.9% of the patients with excision. In 46.7% of the patients, papillomas were excised, a definitive treatment for this process. The supposition for success in the early diagnosis of cancer is close teamwork among the radiology, surgery and pathology services: the diagnostic result depends upon this. We attribute our yield of exact diagnosis to a very sophisticated histological work-up. We believe that this is necessary to avoid diagnostic failures.

[First results of mammography with a screen film (author's transl)]. / Erste Ergebnisse bie der Mammographie mit einem Film-Folien-System.

In order to find a convenient, "dose sparing" mammography method, 152 breasts were examined comparatively with a conventional film without intensifying screens (Definix Medical of Kodak) and with a screen film (screen: MR 50, film: Mammoray RP 3 PE FW of Agfa Gevaert). The quality of the low-dose pictures was generally satisfactory. With regard to the exposure to radiation of the breast which is considerably lower if a screen film is used, it seems necessary to develop an automatic exposure control for this method, to further ameliorate films and screens, and to optimize the technical conditions for mammography. The authors underline the possibility to use simultaneously the oblique exposure methods, which would be a further step towards a reduction of the dose.

[A comparison of various mammographic techniques using freshly amputated breasts (author's transl)]. / Vergleich verschiedener mammographischer Aufnahmetechniken an frisch amputierten Brüsten.

In order to compare the performance of various mammographic techniques, xeroradiograms were obtained of sixteen freshly amputated breasts using tungsten and molybdenum rotating anodes. A film without screens (Kodak Definix Medical) and a film-screen system (screens: MR50, film Mammoray RP 3 PE FW) were employed. Exposures during xeroradiography were varied in that, when using the tungsten tube, a 2.5 mm. aluminium filter was added to the 0.5 mm. aluminium filtration inherent in the tube; when using the molybdenum tube, there was a choice between 0.03 mm. Mo. and 0.5 mm. aluminium filtration. The xeroradiograms obtained with the molydenum tube and molybdenum filter were of good quality, as were those obtained with this type of tube and nonscreen film. In view of the carcinogenetic risk of mammography, it is open to discussion whether one should aim at optimal film quality, since improved quality is associated with a higher radiation dose to the breast, or whether one should be satisfied with "adequate" quality. In our series the quality produced by the film-screen combination was, in general, acceptable. Compared with all other procedures, this system produces the lowest radiation dose of any mammographic technique. For this reason further improvements in technique, such as automatic exosure devices, film-screen packs suitable for routine use and improved quality of image are of practical interest.

[Xeromammography (author's transl)]. / Xeromammographie.

Film- and xeromammography are good diagnostic methods of breast diseases. Concerning praeclinical situations xeromammography is as well as film-mammography. Radiation hazard of xeromammography is on a lower range.

[Thermoluminescent dosimetry for radiation exposure of the breast during film and xeromammography (author's transl)]. / Thermolumineszenzdosimetrische Messungen zur Strahlenexposition der Brust bei Film- und Xeromammographie.

Measurements of radiation exposure of the breast during various mammographic procedures were carried out with LiF dosimeters. Using non-screen film (Kodak Definix Medical) at 30 kv., average skin dose in 105 patients was 10.1 R per exposure. During xeroradiography (45 kv.) skin dose was about 25% of this and for a film-screen system (Mammoray RP 3/MR 50 at 30 kv.) only 7% of this value. Skin dose (at constant potential) rises almost exponentially with increasing tissue thickness. The age of the patient and the type of tissue in the breast has a significant effect on the radiation dose. From the measurements, an average dose per exposure was calculated for the entire breast and for the glandular tissue. This gave a result of 1.6 rd (16 mGy) and 1.0 rd (10 mGy).

[The value of pneumocystography in diagnosis of breast tumours (author's transl)]. / Die Bedeutung der Pneumozystographie in der Abklärung von Mammatumoren.

Pneumocystography was performed regularly in mammographically benign tumours. During 1974 and 1975 16892 breast were investigated radiographically of which 1031 had palpable tumours. In 614 cases the results of palpation correlated with radiography and indicated a cyst. These tumours were punctured with the aim of demonstrating the cyst wall by air filling and subsequent pneumocystography. This procedure enabled 4 out of 10 women (430 out of 1031) to avoid operation despite clinically palpable tumours. In 184 cases biopsy was necessary. In 12 cases the pneumocystogram showed tumours needing excision in addition to unremarkable cysts, in 11 cases the cyst walls showed radiological changes, 161 tumours were apparently solid. Since December 1975 we have started to aspirate breasts with radiographically suspected cysts in the absence of palpable tumour and to perform a pneumocystogram. This attempt was successful in all 19 cases. Removal of unremarkable cysts should not be accepted any longer. Prior to removal of a palpable tumour of the breast radiological investigated is indicated.

[Histological results of lumps excised from the breast after aspiration (author's transl)]. / Histologische Ergebnisse exzisionsbedürftiger Prozesse in punktierten Mammae.

In 614 breasts tumours assumed to be harmless cysts on palpation were aspirated. In 430 cases aspiration was the definitive treatment. In the other 184 cases excision was necessary in order to obtain histology. 11 cysts were radiologically suspect after air filling. In one case excision demonstrated an undifferentiated milk duct carcinoma. 12 cysts had radiologically suspicious areas outside their margins. In 4 cases lobular carcinoma in situ was present. 161 excisions were necessary because no fluid was aspirated at puncture of the tumour. In 10 cases histology showed malignancy: half of these were metastases from a known primary tumour and half were primary breast carcinomas. Out of 17 precancerous states neoplasia could be demonstrated in two cases in addition to papillary and proliferative duct changes. We have classified this neoplasia as lobular carcinoma in situ.