[Experimental investigations for dose reduction by optimizing the radiation quality for digital mammography with an a-Se detector]. / Experimentelle Untersuchungen zur Dosisreduktion durch Optimierung der Strahlungsqualität bei digitaler Vollfeldmammografie mit einem Detektor auf Selenbasis.

PURPOSE: Reduction of radiation exposure at an adequate image quality by optimizing the radiation quality for a new system of full-field digital mammography using a digital detector (a-Se). MATERIALS AND METHODS: The investigations were performed using a digital mammography system Novation (Siemens, Erlangen). The system was constructed with a bimetal anode (molybdenum and tungsten) and the possibility of changing the filter (molybdenum/rhodium). The test object was the Wisconsin Mammography Random Phantom Model 152 A (Radiation Measurements Inc.) of which images were acquired using the digital technique with the tungsten anode and rhodium filter at different tube voltages (26-35 kV) and tube loads (40-100 mAs) and compared to images in the molybdan/molybdan molybdenum/molybdenum technique. To quantify the image quality, we used the detection rate of the simulated lesions in the phantom. RESULTS: Increasing the tube voltage significantly decreases the average glandular dose when using AEC (Automatic Exposure Control), i. e., constant detector dose. At the same time, the image quality decreases significantly with respect to the detection rate (26 kV, 1 mGy, 95.1 %; 35 kV, 0.7 mGy, 82.7 %). As a good compromise between the necessary diagnostic image quality and the lowest dose exposition, 28 kV and 60 mAs were selected for imaging with the tungsten/rhodium anode/filter combination. A further change to the tube load did not make sense because a decrease of 10 % resulted in a significant decrease in the detection rate while only a 2 % increase in detection rate was achieved for a 65 % increase in radiation exposure. CONCLUSION: The results of this phantom study demonstrate that the routine use of the tungsten anode in combination with a rhodium filter for full-field digital mammography with an a-Se detector in contrast to a molybdan/molybdan molybdenum/molybdenum anode/filter combination results in a reduction of the average glandular dose of up to 30 % without loss of diagnostic image quality.

[Comparing the clinical value of spot view mammography with reduced pixel size to monitor zooming by reporting microcalcifications in digital mammography]. / Vergleich der klinischen Wertigkeit von Zielaufnahmen mit reduzierter Pixelgrösse des Detektors und digitalem Monitorzooming bei der Beurteilung von Mikrokalzifikationen in der digitalen Mammografie.

PURPOSE: Evaluation of the diagnostic value of breast specimen imaging with a digital mammographic system using a detector system with changeable pixel size compared to standard mode imaging in different monitor display modes. MATERIALS AND METHODS: Using the digital mammographic system SenoScan (Fischer Imaging, Denver, USA), 50 diagnostic breast specimens with microcalcifications were visualized in both standard mode (pixel size 54 microm) and high resolution mode (pixel size 27 microm). The resulting radiographs were displayed 1:1 on a monitor. Standard mode images (pixel size 54 microm) were additionally displayed in a 2:1 mode. A total of 5 readers with different mammographic experience analyzed the type of the microcalcifications on the basis of the different display modes. The images were presented randomly. The findings were subsequently compared to the histology. RESULTS: The high resolution mode yielded slightly but not significantly better results than the standard mode on average for all 5 readers. Compared to a sensitivity of 80 % and a specificity of 72 % (PPV = 74 %, NPV = 78 %) in the standard mode, the high resolution mode provided a sensitivity of 86 % and a specificity of 74 % (PPV = 77 %, NPV = 83 %). The standard mode images on a 2:1 monitor display yielded 84 % and 74 % (PPV = 76 %, NPV = 82 %). CONCLUSION: The high resolution mode did not significantly increase the sensitivity and specificity of the microcalcification reading. A similar improvement was achieved by the 2:1 display mode, i. e. digital monitor zooming. For the clinical situation this means that there is no diagnostic advantage from using a high resolution target view with this mammographic system.

Experimental phantom lesion detectability study using a digital breast tomosynthesis prototype system.

PURPOSE: To compare the sensitivity of conventional two-dimensional (2D) projection imaging with tomosynthesis with respect to the detectability of mammographic phantom lesions. MATERIALS AND METHODS: Using a breast tomosynthesis prototype based on a commercial FFDM system (Siemens MAMMOMAT Novation), but modified for a wide angle tube motion and equipped with a fast read-out amorphous selenium detector, we acquired standard 2D images and tomosynthesis series of projection views. We used the Wisconsin mammographic random phantom, model RMI 152A. The anode filter combinations Mo/Mo and W/Rh at two different doses were used as typical radiographic techniques. Slice images through the phantom parallel to the detector were reconstructed with a distance of 1 mm employing a filtered back-projection algorithm. The image data sets were read by five radiologists and evaluated with respect to the detectability of the phantom details. RESULTS: For all studied radiographic techniques, the detection rate in the tomosynthesis mode was 100 %, i. e. 75 true positive findings out of 75 possible hits. In contrast, the conventional projection mode yielded a detection rate between 80 and 93 % (corresponding to 60 and 70 detected details) depending on the dose and X-ray spectrum. CONCLUSION: Tomosynthesis has the potential to increase the sensitivity of digital mammography. Overlapping structures from out-of-plane tissue can be removed in the tomosynthesis reconstruction process, thereby enhancing the diagnostic accuracy.

Evaluation of low-cost computer monitors for the detection of cervical spine injuries in the emergency room: an observer confidence-based study.

BACKGROUND: To compare the diagnostic value of low-cost computer monitors and a Picture Archiving and Communication System (PACS) workstation for the evaluation of cervical spine fractures in the emergency room. METHODS: Two groups of readers blinded to the diagnoses (2 radiologists and 3 orthopaedic surgeons) independently assessed-digital radiographs of the cervical spine (anterior-posterior, oblique and trans-oral-dens views). The radiographs of 57 patients who arrived consecutively to the emergency room in 2004 with clinical suspicion of a cervical spine injury were evaluated. The diagnostic values of these radiographs were scored on a 3-point scale (1 = diagnosis not possible/bad image quality, 2 = diagnosis uncertain, 3 = clear diagnosis of fracture or no fracture) on a PACS workstation and on two different liquid crystal display (LCD) personal computer monitors. The images were randomised to avoid memory effects. We used logistic mixed-effects models to determine the possible effects of monitor type on the evaluation of x ray images. To determine the overall effects of monitor type, this variable was used as a fixed effect, and the image number and reader group (radiologist or orthopaedic surgeon) were used as random effects on display quality. Group-specific effects were examined, with the reader group and additional fixed effects as terms. A significance level of 0.05 was established for assessing the contribution of each fixed effect to the model. RESULTS: Overall, the diagnostic score did not differ significantly between standard personal computer monitors and the PACS workstation (both p values were 0.78). CONCLUSION: Low-cost LCD personal computer monitors may be useful in establishing a diagnosis of cervical spine fractures in the emergency room.

[Digital mammography with high-resolution storage plates (CR) versus full-field digital mammography (CCD) (DR) for microcalcifications and focal lesions -- a retrospective clinical histologic analysis (n = 102)]. / Digitale Mammographie mit hochauflösenden Speicherfolien (CR) versus digitaler Vollfeldmammographie (CCD) (DR): Mikrokalzifikationen und Herdbefunde -- eine retrospektiv klinisch-histologische Analyse (n = 102).

PURPOSE: To determine the diagnostic accuracy of microcalcifications and focal lesions in a retrospective clinical-histological study using high-resolution digital phosphor storage plates (hard copy) and full-field digital mammography (hard copy). MATERIALS AND METHODS: From May 2003 to September 2003, 102 patients underwent digital storage plate mammography (CR), using a mammography unit (Mammomat 3000 N, Siemens) in combination with a high resolution (9 lp/mm) digital storage phosphor plate system (pixel size 50 microm) (Fuji/Siemens). After diagnosis and preoperative wire localization, full-field digital mammography (CCD) (DR) was performed with the same exposure parameters. The full-field digital mammography used a CCD-detector (SenoScan) (Fisher Imaging) with a resolution of 10 Ip/mm and a pixel size of 50 microm. Five investigators determined the diagnosis (BI-RADS I - V) retrospectively after the operation from randomly distributed mediolateral views (hard copy reading). These results were correlated with the final histology. RESULTS: The diagnostic accuracy of digital storage plate mammography (CR) and full-field digital mammography (CCD) (DR) was 73 % and 71 % for all findings (n = 102), 73 % and 71 % for microcalcifications (n = 51), and 72 % and 70 % for focal lesions (n = 51). The overall results showed no difference. CONCLUSION: Our findings indicate the equivalence of high-resolution digital phosphor storage plate mammography (CR) and full-field digital mammography (CCD) (DR).

[Phantom study for the detection of simulated lesions in five different digital and one conventional mammography system]. / Phantomstudie zur Detektion simulierter Läsionen an fünf verschiedenen digitalen und einem konventionellen Mammographiesystem.

PURPOSE: Experimental phantom study for the detection of simulated lesions with five different digital and one conventional screen-film mammography system. MATERIALS AND METHODS: Three radiographs were obtained at various configurations of the phantom with one conventional screen-film system (Mammomat 3000 N) (Siemens), five digital systems (high resolution computed radiography system [Fuji/Siemens], one a-Si detector [GE Medical Systems], two a-Se detectors [Siemens; Hologic / Lorad] and one CCD detector [Fischer Imaging]), applying the same exposure parameters. The Wisconsin Mammographic Random Phantom, Model 152 A, was used. Five investigators with different experience in mammography (3 months to more than 4 years) evaluated the 18 randomly selected radiographs. RESULTS: No significant differences were found in the detection rate of simulated breast lesions for conventional screen-film mammography (84.9 %), high resolution computed radiography (86.7 %) and digital mammography with an a-Si detector (89.8 %). Highly significantly better results (p < 0.001) were found with the two a-Se systems (97.3 %) and the CCD system (100 %). CONCLUSION: Conventional screen-film mammography can be replaced by high resolution computed radiography and digital mammography with a-Si-, a-Se- and CCD-detectors. This has to be confirmed in further clinical studies.

The role of vision in maintaining heading direction: effects of changing gaze and optic flow on human gait.

How is heading direction maintained in human gait? This question was investigated with respect to the role of optic flow and in the context of different movement strategies. While walking on a treadmill the deviation from the ideal straight path was measured in terms of lateral sway induced by a lateral gaze shift (by looking at a moving visual target). The role of the focus of expansion (FOE) within a radially expanding optic flow pattern was investigated by varying its relative velocity of expansion from 0- to 4-fold (the equivalent of walking speed), thus increasing the perceptibility of FOE. If FOE was a relevant cue for maintaining heading direction, a reduction of lateral sway amplitude was expected with increasing flow velocity. The presence of a radially expanding flow pattern did not reduce lateral sway. Lateral sway was least when the visual background remained stable without any flow pattern. Increasing the velocity of the flow pattern resulted in an increase in lateral sway. If the relative velocity of the flow pattern was raised beyond that corresponding to walking speed, lateral sway amplitude approached the maximal values observed in the dark. In all experiments, sway amplitude increased linearly with the increasing excursion of the visual target. Different strategies to perform the gaze shift (eye or head turns) only resulted in minor differences in lateral sway amplitude. The results show that gaze shifts during locomotion induce lateral sway, which depends upon the presence, and characteristics, of background optic flow. Under the present conditions, the FOE within the flow field seems not to be a dominant cue to control heading. However, the systematic increase in lateral sway induced by high flow velocities indicates that motion parallax has an effect on heading during locomotion.

Experimental investigations of image quality in X-ray mammography with conventional screen film system (SFS), digital phosphor storage plate in/without magnification technique (CR) and digital CCD-technique (CCD).

Comparison of image quality in X-ray mammography between conventional film screen film system (SFS), digital phosphor storage plate in and without magnification technique (CR) and digital CCD-technique (CCD). Radiograms of an RMI-mammography phantom were acquired using a conventional screen film system, three digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were post-processed regarding contrast and included in the comparison. The detectability of details was best with the digital mammography in CCD-technique. After confirming these promising results in clinical studies, digital mammography should be able to replace conventional screen film technique.

[Experimental studies on image quality in conventional film screen system, digital phosphor storage plate mammography in mangnification technique and digital mammography in CCD-technique]. / Experimentelle Untersuchungen zur Bildgüte konventioneller Film-Folien-Mammographie, digitaler Mammographie mit Speicherfolien in Vergrösserungstechnik und voll digitaler Mammographie in CCD-Technik.

UNLABELLED: Comparison of image quality between conventional film screen system, digital phosphor storage plate mammography in magnification technique and digital mammography in CCD-technique. MATERIALS AND METHODS: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system, two digital storage plate systems and two digital systems in CCD-technique. Additionally, the radiograms of one digital phosphor storage plate system were postprocessed emphasizing contrast and included in the comparison. RESULTS: The detectability of details was the best with the digital mammography in CCD-technique in comparison with the conventional film screen technique resp. digital phosphor storage plate in magnification technique. CONCLUSIONS: Based on these results there is the possibility to replace the conventional film screen system by further studies--this has to be confirmed.

[Image quality and radiation exposure in digital mammography with storage phosphor screens in a magnification technic]. / Bildgüte und Strahlenexposition bei der digitalen Mammographie mit Speicherfolien in Vergrösserungstechnik.

PURPOSE: Comparison of image quality between digital phosphor storage plate mammography in magnification technique and a conventional film screen system regarding the special aspect of radiation exposure. MATERIALS AND METHODS: Radiograms of a RMI-mammography phantom were acquired using a conventional film screen system and two digital storage plate systems. Additionally, the radiograms of one digital system were post-processed emphasizing contrast and included in the comparison. RESULTS: The detectability of details in storage plate mammographies with magnification technique is almost equal to that of film screen mammographies. Thereby, lower radiation exposures were necessary using the digital systems. CONCLUSIONS: Based on these results, storage plate mammography in magnification technique is used in clinical routine at our institution. The correct parameters in image postprocessing are of elementary importance for detail detectability. Future studies must show, whether the lower radiation exposure in digital radiograms of the breast, revealing much higher background noise, will allow the same detail detectability as film screen mammographies.

Identification of Mycobacterium shimoidei in a tuberculosis-like cavity by 16S ribosomal DNA direct sequencing.

A new, well-documented case of Mycobacterium shimoidei infection is reported. This bacterium was isolated from a patient with preexisting pulmonary lesions who developed a tuberculosis-like cavity in the lung. Isolation of fewer than ten strains, not epidemiologically related, has been reported worldwide; all originated from human pulmonary samples. Identification of the strain described here was first accomplished by 16S rDNA direct sequencing after in vitro amplification. This method allows rapid identification of unusual bacteria. The identification was confirmed by specific phenotypical tests and by chromatographic methods.

[Contribution of an induction treatment in the surgical treatment of locally advanced non-small-cell cancers]. / Apport d'un traitement d'induction dans le traitement chirurgical des cancers non microcellulaires localement avancés.

From October 1988 to July 1990, 18 patients with marginally resectable non-small cell cancer (10 stage IIIa and 8 stage IIIb) were entered in a phase-II trial combining induction therapy with a subsequent thoracotomy. Induction therapy included 2 courses of chemotherapy (5-FU and cisplatinum) and radiotherapy (30 Gray in split course). Partial response was observed in 10 patients, and minimal response in 3. Thoracotomy disclosed unresectability in 3 patients. Fifteen complete resections consisted in 1 lobectomy and 14 pneumonectomies. There were no operative deaths (30 days). Postoperative recovery was uneventful in 3 patients with exploratory thoracotomy and in 1 patient with lobectomy. Following pneumonectomy, we observed 2 bronchopleural fistulae and 1 empyema. On pathology, 10 patients were stage IIIa, and 3 were stage I, whereas no residual tumor was found in 2 patients. During follow-up, local recurrence occurred in 2, and metastases in 8. On December 31st, 1993, 3 patients were alive at 44, 52, and 62 months respectively. Nine patients had died from cancer, and 3 from unrelated causes. Estimated survival was 66.7% at 1 year, 33.3% at 3 years, and 20% at 5 years. We conclude that induction therapy allowed satisfactory resection for marginally resectable tumors. Operative morbidity was increased in this group. However, the 5-year survival was similar to resectable stage IIIa cancer.

[Evaluation of the prognosis in sarcoidosis: remission as an issue of biological criteria and current cellular activities (ACE and alveolar lymphocytosis)]. / Evaluation du pronostic de la sarcoïdose: remise en question des critères biologiques et cellulaires usuels d'activité. (ECA et lymphocytose alvéolaire).

The spontaneous evolution of 60 patients suffering from recently diagnosed sarcoidosis was compared with their initial biological profile of "activity". 47% of this unselected group of patients belonged to an inactive group (ACE less than 35 nmol/ml/mn and the percentage of alveolar lymphocytes less than 30%). After a mean period of two years of follow up it turned out that the initial bioprofile of activity had no predicted value, even in the absence of any initial elevation of the markers (3 cases out of 28 grew worse). The repeated controls of criteria of activity did not objectively show any concordant change with the outcome in such cases. It is necessary to point out the unfavourable character of very raised ACE activity greater than 50 nmol/ml/mn (7 deteriorations out of 8 cases). It would appear that a systematic search for these criteria should be deferred principally in type 1 lymph node involvement or pulmonary and mediastinal type IIA, all the more so as in practice they have little influence on therapeutic decisions.

[Multiple elemental organic components of the broncho-alveolar lavage fluid in normal subjects and in various lung pathologies (excluding silica and asbestos fibers)]. / Etude multi-élémentaire des composants inorganiques du liquide de lavage broncho-alvéolaire chez le sujet normal et dans diverses pathologies pulmonaires (silice et fibres d'amiante exclues).

Owing to a technical analysis enabling the detection of mineral elements present in trace amounts in small volumes, an analysis of the liquid obtained in 148 broncho-alveolar lavages could be studied. The elements consistently recovered were as follows: iron, copper, zinc, nickel, lead and titanium. Normal values were established. In the absence of exposure, there was no significant difference distinguishing the different pulmonary diseases studied. In occupational disease, the presence of iron in large quantities, tungsten, nickel and rare earths could be shown objectively, as well as the persistence of gold or iodine after medical absorption. However, this preliminary work does not allow one to establish a formal correlation between the alveolar concentrations obtained and the pulmonary disease observed.

Transbronchial needle aspiration in the diagnosis of sarcoidosis.

A total of 258 patients with suspected sarcoidosis underwent transbronchial needle aspiration lymph node biopsies and forceps bronchial biopsies during rigid bronchoscopy. Transbronchial needle aspiration biopsies revealed noncaseating granulomas in 66.3 percent of patients. When transbronchial needle aspiration biopsies were combined with forceps bronchial biopsies, the positive rate increased to 77.7 percent. No major complication occurred when using transbronchial needle aspiration. Rigid bronchoscopy with transbronchial needle aspiration biopsies appears to offer a sensitive and specific alternative to more invasive techniques used in the diagnosis of sarcoidosis.

[5-year survival of resected bronchial cancer. Multifactorial analysis of its prognosis]. / Survie à 5 ans du cancer bronchique opéré. Analyse multifactorielle du pronostic.

Prognosis in patients having undergone surgery for a bronchial carcinoma (oat cell. carcinoma excluded) was studied by comparing, with two statistical methods, a group of 178 patients surviving five years and more (group I) and a group of 178 patients who died within five years (group II). The two groups had undergone treatment during the same period. Comparison of the two groups suggested that the following factors were indicators of a good prognosis: ratio weight-height within normal limits without recent weight loss, fortuitous detection of the carcinoma; normal aspect on bronchoscopy; T1 N0 type without vascular extension, limited exeresis. Recurrences of the carcinoma were generally observed in group II but could be present in group I. The differential prognosis between pulmonary metastases and a "new" bronchial carcinoma was difficult. Survival was finally determined by the frequency of recurrences and metastases. By a correspondences factorial analysis it was possible to separate and to define the main characteristics of the patients with a good prognosis and a long survival and of those with a poor prognosis and a short survival. However this proved to be exact in only 30% of the individual cases because occurrence of metastases was generally unforeseable. From these data it appears that surgery alone is indicated in only one kind of tumours; T1 N0 carcinomas detected by routine examinations.

[Transbronchial lymph node biopsy in the diagnosis of sarcoidosis (author's transl)]. / La biopsie ganglionnaire transbronchique dans le diagnostic de la sarcoïdose.

Two hundred and fifty eight transbronchial lymph node biopsies using a Menghini type needle 1.5 mm in diameter were performed in 193 patients with a radiological and clinical picture suggestive of sarcoidosis. In 73 cases, the histological argument for the diagnosis was provided solely by this technique. The combination of two methods of obtaining material (multiple biopsies and transbronchial puncture) during rigid bronchoscopy led to a histological diagnosis in 77.7% of patients. The authors emphasize the relative safety of the method, as well as its value when material obtained by fibroscopy has proven to be unsatisfactory.

[Indication or surgical abstention in the treatment of emphysematous bullae (author's transl)]. / A propos de l'indication ou de l'abstention chirurgicale dans le traitement des bulles d'emphysème.

During a 9-year period from 1968 to 1977, in the case of bullae measuring at least 10 cm diameter, 21 surgical interventions and 31 conservative treatments were performed. The indications were either peremptory (irreductible pneumothorax, acute extension of the bullae) or spontaneously determined using a series of detailed criteria. The frequency of bronchial cancer occurring in the emphysematous bullae is noteworthy (8 cases out of 55 observations).