Mammographic screening in southern California: 2 1/2-year longitudinal survey of fees

The American Cancer Society sponsored a community-wide low-cost mammographic screening project in March 1986. One of the major goals was to effect a decrease in mammographic screening fees. To evaluate the effectiveness of the project, a telephone survey of 58 facilities was conducted six times over 2 1/2 years, beginning January 1986 and at 6-month intervals thereafter. The number of facilities offering lower fees for screening than for consultative mammography increased from two with a mean fee of $50.00 in January 1986 to 16 with a mean fee of $68.71 in July 1988. The trend for differentiating screening and consultative examination fees occurred at both hospital- and office-based practices, but fees were significantly lower in the office-based practices. There was also a statistically significant increase in the number of facilities accepting self-referred patients between January 1986 (15.5% of facilities) and July 1988 (34.5%). At the time of the last survey, 60% of office-based practices were accepting self-referred patients.     

Assisted ventilation and survival of extremely low birthweight infants

Objective : To determine the incremental consumption of ventilator resources associated with the improving survival rate of extremely low birthweight (ELBW, birthweight 500–999 g) infants, from the time assisted ventilation was introduced. Methodology : Cohort study of ELBW infants born in one tertiary perinatal centre (The Royal Women's Hospital, Melbourne). All ELBW infants born from 1971 to 1993 were included in the study. Inhospital survival rates and patient-days of assisted ventilation were the main outcome measures. Discrete eras of relatively stable survival rate and consumption of ventilator resources were identified. These comprised the years 1971–74, 1977–83, 1985–90, and 1992–93. Cost-effectiveness ratios (the incremental consumption of ventilator resources per additional survivor) were calculated between adjacent eras by dividing the increment in the consumption of ventilator resources by the increment in the survival rate. Results : The survival rates rose progressively between eras (6.2, 33.9, 49.1, 68.8%, respectively, as did the consumption of ventilator resources (0.1, 6.6, 16.2, 24.7 patient-days of assisted ventilation per livebirth, respectively). The cost-effectiveness ratio deteriorated initially, increasing from 23.2 to 63.5 additional patient-days of assisted ventilation per additional survivor, but then improved, falling to 43.1 additional patient-days of assisted ventilation per additional survivor in the last era. These changes were even more marked for those of birthweight 750-999 g (20.0, 63.2 to 35.9 additional patient-days of assisted ventilation per additional survivor, respectively). In contrast, the cost-effectiveness ratio was initially worse for those of birthweight 500-749 g, being three-fold higher than for the larger infants, and only improved substantially in the last era (59.8, 58.3 to 44.1 additional patient-days of assisted ventilation per additional survivor, respectively). Conclusions : The initial deterioration in cost-effectiveness ratios between successive eras probably reflected the increased availability of resources for assisted ventilation, without any other major advances in perinatal care. The improvement in cost-effectiveness in the last era reflected, in part, the increased use of antenatal steroid therapy and the introduction of exogenous surfactant to neonatal intensive care.     

Popliteal venous aneurysm

Two new cases of popliteal venous aneurysm, confirmed with findings from venography, are added to seven previously reported cases revealed in the authors' search of the English-language literature. This rare anomaly usually shows as recurrent pulmonary emboli in patients with no underlying predisposition to deep venous thrombosis. Physical examination is usually not helpful in the diagnosis. Results of combined real-time and Doppler ultrasound should indicate the diagnosis, but venography is necessary for confirmation and further anatomic detail. Surgical treatment has been fraught with complications. Eight patients, including these two new cases, have undergone surgery, and none have had a recurrence of pulmonary embolism following surgery.     

Anatomy of the hip: correlation of coronal and sagittal cadaver cryomicrosections with magnetic resonance images

Summary Magnetic resonance imaging (MRI) is noninvasive and provides images with higher soft tissue contrast than possible with any other imaging modality. Unlike CT which depicts anatomy in the axial plane, MRI is capable of producing images in thin cross sections acquired directly in any plane, usually axial, coronal or sagittal planes. The use of diagnostic MR images is facilitated by an understanding of the detailed anatomy that is depicted. The purpose of this study was to identify anatomical structures in coronal and sagittal cryomicrosections of the hip region. Thin cryosections of the hips of fresh-frozen cadavers were obtained by a method developed by one of the authors (WR). These sections were matched with thin-section, high resolution MR images of a normal volunteer. The complex anatomy of the hip and its surrounding muscles, tendons and ligaments was exquisitely depicted on both the cadaver microcryosections and the matched MRT images.

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Anatomie de la hanche: corrélation entre les microsections et les résultats de l'imagerie en résonance magnétique

Résumé L'imagerie en résonance magnétique (IRM) est une technique non invasive qui permet d'obtenir des images des parties molles avec un contraste plus élevé que toutes les autres techniques. A la différence du scanner qui décrit l'anatomie dans le seul plan axial transverse, l'IRM est capable de donner des images en coupes fines obtenues directement dans n'importe quel plan: couramment dans les plan axial, transverse et sagittal. L'interprétation des images IRM est facilitée par la compréhension de l'anatomie détaillée de la région étudiée. Le propos de ce travail est d'identifier les structures anatomiques dans des plans de coupes sagittales et coronales de la région de l'articulation coxo-fémorale. Des coupes fines de pièces congelées ont été obtenues à partir de douze cadavres selon une méthode mise au point par l'un des auteurs (WR). Ces sections ont été comparées avec des coupes IRM fines faites en haute résolution chez un volontaire sain. L'anatomie complexe de la hanche et des muscles qui l'entourent ainsi que des tendons et des ligaments est décrite avec précision sur les coupes anatomiques et les images IRM.

     

Vena caval filter splaying: potential complication of use of the titanium Greenfield filter

Significant structural and mechanical differences exist between the titanium and stainless steel versions of the Greenfield filter (GF). The titanium GF has a longer leg length (49 mm vs 43 mm), a greater span (38.5 mm vs 28.0 mm), and a larger hook angle (41 degrees vs 23.5 degrees). In vitro tests demonstrated approximately sevenfold greater filter length shortening (a measure of filter splaying) for the titanium GF in response to a given applied load. These differences resulted in marked filter splaying and inferior vena cava (IVC) perforation in three patients in whom a titanium GF had been inserted. The aorta was penetrated by a filter leg in one patient, and abdominal or back pain was present in all three patients. In vitro tests involving thrombosis within a latex balloon revealed that the titanium GF, but not the stainless steel GF, remained splayed even in the face of clot retraction. Design modifications, possibly using shorter, thicker filter legs and using reduced hook angles, should be made in the titanium GF to decrease the risk of filter splaying and IVC perforation before widespread use of this device.