Mailing strategies and recruitment into an intervention trial of the exercise effect on breast cancer biomarkers.

Recruitment into public health intervention trials can be costly and time-consuming. We examined two components of recruitment for an exercise trial: (a) a randomized pilot study of mailing strategies; and (b) the results from the entire recruitment process. In the pilot study, 4,999 women were randomized into one of four groups using a factorial design. The first factor was the inclusion or exclusion of a personal invitation letter, and the second was the use of first-class stamps versus bulk mail. We received 580 (11.6%) responses. Responses from interested women were nonsignificantly higher (odds ratio, 1.19; P = 0.10) for first-class versus bulk-rate postage. However, the cost to randomize one participant using first-class mail was $56.14 (in 1998 dollars) more than for bulk mail. We found no difference in response when including the invitation letter (odds ratio, 1.00; P > 0.50). The general recruitment process identified potentially eligible women primarily through mass mailings but also through media and other sources. We mailed recruitment materials, via bulk mail and including an invitation letter, to 103,577 women in the Seattle area over 2 years. Response rates were different (P < 0.001) between age groups: 6.2% for 50-59-year-old women; 7.9% for 60-69-year-old women; and 7.4% for 70-75-year-old women. The proportion of respondents eventually randomized did not differ by recruitment strategy (mail, media, other). Our study indicates that bulk mail may be more cost-effective than first-class mail for recruitment into intervention trials and that older women are willing to participate in such studies.     

Are equally spaced specimen collections necessary to assess biological variation? Evidence from renal transplant recipients

The established method for determining the components of biological variation (BV) requires equispaced time intervals between samplings. In a previous study, we determined BV in renal post transplantation patients, taking advantage of the samples obtained within their clinical treatment protocol (not necessarily equispaced). To confirm the validity of this practice, we sought to determine if the use of varying sampling intervals has an effect on the results obtained in such biological variation studies. The study included two phases: comparison of the results found with identical and non-identical sampling intervals and correlation between the within-subject BV and the length of the sampling interval. There were no differences in within-subject BV between the groups or correlations with sampling intervals for any of the constituents studied. We conclude that samples acquired within established clinical protocols for kidney transplant recipients can be used for estimating BV.     

The role of standby emergency medication for falciparum malaria: current opinion

Travellers to malaria-endemic destinations are at risk of significant disease and, sometimes, death. Current malaria protection strategies, including chemoprophylaxis, can never be completely effective. In some cases, protective measures are discontinued or misapplied while the risk of infection still exists. In others, suboptimal measures are used, or even no measures at all, because of poor information or inappropriate risk-benefit assessment. In very rare cases, inexplicable failure of prophylaxis occurs. If malaria is contracted whilst abroad the danger to the individual is often further compounded by a lack of high-quality medical facilities and an uncertain supply of effective drugs for treatment. The advent of newer, well tolerated, drugs for treating malaria provides an opportunity to review the role of standby emergency self-medication in travellers visiting or staying (for work or other reasons) in areas where there is a risk of contracting malaria. This article was prepared following a meeting convened in London on Africa Malaria Day in 2002, in which the current opinions of experts in travel medicine and specifically malaria were discussed. It reviews opinion on the current effectiveness and acceptance of prevention strategies, as well as the role of standby emergency medication for falciparum malaria.     

External auditory canal cholesteatoma: clinical and imaging spectrum

BACKGROUND AND PURPOSE: Cholesteatoma is an inflammatory lesion of the temporal bone that uncommonly involves the external auditory canal (EAC). In this large case series, we aimed to define its imaging features and to determine the characteristics most important to its clinical management. METHODS: Thirteen cases of EAC cholesteatoma (EACC) were retrospectively reviewed. Clinical data were reviewed for the history, presentation, and physical examination findings. High-resolution temporal bone CT scans were examined for a soft-tissue mass in the EAC, erosion of adjacent bone, and bone fragments in the mass. The middle ear cavity, mastoid, facial nerve canal, and tegmen tympani were evaluated for involvement. RESULTS: Patients presented with otorrhea, otalgia, or hearing loss. Eight cases were spontaneous, and five were postsurgical or post-traumatic. CT imaging in all 13 cases showed a soft-tissue mass with adjacent bone erosion. Intramural bone fragments were identified in seven cases. This mass most often arose inferiorly (n = 8) or posteriorly (n = 8), but it was circumferential in two cases. We noted middle ear extension (n = 5), mastoid involvement (n = 4), facial canal erosion (n = 2), and tegmen tympani dehiscence (n = 1). CONCLUSION: Temporal bone CT shows EACC as a soft-tissue mass within the EAC, with adjacent bone erosion. Bone fragments may be present within the mass. The cholesteatoma may extend into the mastoid or middle ear, or it may involve the facial nerve canal or tegmen tympani. Recognition of this entity and its possible extension is important because it may influence clinical management.     

Giant ranula of the neck: differentiation from cystic hygroma

BACKGROUND AND PURPOSE: Occasionally, diving ranulas may attain large dimensions (giant ranula); gross involvement of the submandibular and parapharyngeal spaces makes differentiation from other cystic neck masses, particularly cystic hygroma, difficult. As diving ranula and cystic hygroma are managed with different surgical approaches, avoidance of this pitfall is critical. Our purpose was to review the imaging findings of giant ranula and compare them with those of cystic hygroma to define those features that are helpful in differentiating these different disease entities. METHODS: We conducted a retrospective review of all cases of ranulas that had been surgically treated at our institution in a 15-year period. These were compared with cases of cystic hygroma that involved the same anatomic regions. Images were analyzed for anatomic location and morphology, with specific attention paid to those characteristics that might assist differentiation. Giant ranula was defined as any ranula that significantly involved the paraphyngeal space in addition to the submandibular space. RESULTS: Six patients with giant ranula and fifteen patients with cystic hygroma were reviewed. All giant ranulas retained tapered communication with the sublingual space and were homogeneous, thin-walled, anatomically defined, fluid-containing masses. One infected lesion enhanced, and another previously operated lesion demonstrated mild septation. Cystic hygroma commonly did not communicate with the sublingual space and had features of lobulation, septation and heterogeneity. Additional involvement of spaces not typically involved by ranula further assisted differentiation. CONCLUSION: Although giant ranulas may superficially resemble cystic hygroma, several imaging features allow confident differentiation of these two entities.     

Initiating informatics and GIS support for a field investigation of Bioterrorism: The New Jersey anthrax experience

Background  

The investigation of potential exposure to anthrax spores in a Trenton, New Jersey, mail-processing facility required rapid assessment of informatics needs and adaptation of existing informatics tools to new physical and information-processing environments. Because the affected building and its computers were closed down, data to list potentially exposed persons and map building floor plans were unavailable from the primary source.     

Earring lesions of the parotid tail

BACKGROUND AND PURPOSE: Masses in the parotid tail can be a source of consternation to radiologists and clinicians; inaccurate localization may lead to significant iatrogenic complication. We sought to review the pertinent anatomic localizing features of the parotid tail, relevant facial nerve anatomy, and sources of clinical and radiologic confusion. To conclude, we review imaging features that are helpful in generating a diagnosis in this location. METHODS: We retrospectively reviewed the imaging and clinical features of 111 parotid tail masses in 103 patients (56 male, 45 female, two of unknown sex; age range, 5 months-81 years). The following imaging findings were noted: size, enhancement, multiplicity of lesions, attenuation on CT scans, signal intensity on MR images, and appearance of the surrounding parotid gland. Diagnosis was confirmed by either surgical resection or biopsy findings or by specific clinical data or characteristic imaging findings. RESULTS: Seventeen types of parotid tail masses were identified. Benign lesions were: pleomorphic adenoma (n = 15), Warthin tumor (n = 14), infectious process (n = 13), venous malformation (n = 9), and Sj?gren disease (n = 9), lymphatic malformations (n = 7), lipoma (n = 6), HIV lymphoepithelial lesion (n = 4), first brachial cleft cyst (n = 3), oncocytoma (n = 2), sarcoid (n = 1), and lymph node (n = 1). Malignant lesions were: Non-Hodgkin lymphoma (n = 14), metastatic disease (n = 7), mucoepidermoid carcinoma (n = 4), acinic cell carcinoma (n = 1), and undifferentiated carcinoma (n = 1). Eight patients had two diagnoses. CONCLUSION: Understanding normal parotid tail anatomy is important to radiologists, because accurate localization has implications for appropriate management of masses in this location, potentially reducing the occurrence of marginal mandibular nerve injury.     

Use of personal digital assistants for retrieval of medical images and data on high-resolution flat panel displays.

For its new acute care hospital, the University of California at Los Angeles is evaluating innovative technology involving high-resolution flat panel display devices configured as "network appliances" that can be wall mounted for use in the retrieval and display of medical images and data. Physicians and healthcare providers can log on with wireless handheld computers, which can serve as an identification device as well as a navigational tool for selecting patient records and data. These data are displayed and manipulated on the flat panel display without the need for a keyboard or mouse. A prototype was developed with commercially available image display software, which was modified to allow the remote control of software functions from a handheld device through an infrared communication port. The system also allows navigation through the patient data in a World Wide Web-based electronic patient record. This prototype illustrates the evolution of radiologic facilities toward "shareable" high-quality display devices that allow more convenient and cost-effective access to medical images and related data in complex clinical environments, resulting in a paradigm shift in data navigation and accessibility. Copyright RSNA, 2003.