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L L Fajardo

Publications and source records attributed to L L Fajardo.

At least 55 records · Page 3Linked to original sources
PubMed1992

Diagnostic performance of teleradiology in cervical spine fracture detection.

This study was done to assess the diagnostic accuracy of high-resolution (5 lp/mm) teleradiology for detecting cervical spine fractures. Single radiographs from 25 patients with and 25 patients without cervical spine fractures were transmitted between two units of our teleradiology system (Dupont DTR 2000) located 5 miles apart. Each image was examined by four readers. Fracture detection accuracy was assessed by generating receiver operating characteristic (ROC) curves and comparing the areas under each reader's curves for original and transmitted images. Two readers had statistically significant better fracture detection using nontransmitted images, whereas two had no significant differences in accuracy. The authors conclude that high resolution in and of itself is not adequate for fracture detection, and that issues concerning image contrast manipulation also will have to be addressed before teleradiology systems can be used for clinical cervical spine fracture screening.

Cervical Vertebrae↗
PubMed1992

Factors influencing women to undergo screening mammography.

Despite the fact that mammography is a valuable tool for early detection of breast cancer, the majority of age-eligible American women do not avail themselves of screening mammography. To better understand why women do or do not undergo mammography and to further develop guidelines for promoting breast cancer screening, the authors investigated what impact personal factors, attitudes, and health-related behaviors have on compliance with screening mammography by surveying 521 women for information related to health behavior, health concerns, sense of well-being, satisfaction with health care, and knowledge about breast cancer. Women who underwent mammography were more likely to have a regular physician, to practice breast self-examination, to be less concerned over the cost of mammography, to be generally satisfied with their health care, to believe they have a greater sense of control over their health, and to be more knowledgeable about mammography and breast cancer. Age, health behavior, sense of well-being, locus of control, and breast cancer experience helped differentiate between women who had undergone mammography and those who had not.

Adult↗
PubMed1992

Efficacy of digital radiography for the detection of pneumothorax: comparison with conventional chest radiography.

As part of our continuing evaluation of the clinical applicability of digital radiography, we compared the abilities of radiologists to detect pneumothoraces on conventional chest radiographs with their performances when using three formats of digitally obtained images. Twenty-three frontal-view chest radiographs with pneumothoraces and 22 other chest radiographs, either normal or showing miscellaneous abnormalities, were interpreted by five experienced radiologists in each of four formats: conventional film-screen chest radiographs, small-format (17.8 x 21.6 cm) computed radiographs, large-format (35.6 x 43.1 cm) computed radiographs, and digital images viewed on an interactive electronic workstation. The receiver-operating-characteristic curve areas for each observer for the four types of images were compared by a z test on a critical ratio, and the mean sensitivity and specificity values were compared by the sign rank test. The mean areas under the receiver-operating-characteristic curves ranged from 0.869 for the digital workstation to 0.915 for film-screen images. The differences observed among formats were not statistically significant. Mean specificities also were not significantly different, ranging from 0.90 for large-format computed radiographs to 0.96 for the digital workstation. Mean sensitivity ranged from 0.65 for the digital workstation to 0.82 for film-screen images. Radiologists interpreting digital workstation images were significantly less sensitive in detecting pneumothoraces than with film-screen and small-format computed images (p = .06). In this study, radiologists detected pneumothoraces equally well on conventional film-screen radiographs and digital images printed on film; however, they detected pneumothoraces less well on electronic viewing consoles. This latter finding reflects an important practical difference in the working behavior of radiologists interacting with a digital workstation.

Humans↗
PubMed1992

Interventional procedures in diseases of the breast: needle biopsy, pneumocystography, and galactography.

This article discusses the roles of mammography-guided needle biopsy of the breast, pneumocystography, and galactography in further defining breast lesions that have been detected with mammography. For each procedure, indications for its use, proper technique, complications, interpretation, and role in clinical practice are described. Use of these procedures is warranted for some patients to provide detail beyond that available with mammography and sonography.

Adult↗
PubMed1990

Altered gastric and duodenal motility in intestinal obstruction.

There are no strict clinical or radiographic criteria that consistently indicate imminent strangulation in cases of small bowel obstruction. An intestinal obstruction with vascular compromise produces a marked retention of food, fluid, or contrast material in the stomach and duodenum, while an obstruction without vascular problems may show no change or somewhat delayed gastric emptying with some duodenal hypotonia. The association of gastric atony and profound stomach dilatation with strangulating, usually closed-loop intestinal obstruction, has generally not been appreciated by radiologists. We illustrate this phenomenon in 4 patients and emphasize its usefulness in evaluating intestinal obstructions.

Adult↗
PubMed1990

Prospective comparison of plain abdominal radiography with conventional and digital renal tomography in assessing renal extracorporeal shock wave lithotripsy patients.

Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.

Humans↗
PubMed1990

Research and research training in academic radiology departments. A survey of department chairmen.

We surveyed 121 chairmen of academic radiology departments to assess how these departments select and educate their residents and fellows in research. Eighty-six chairmen responded (71%). The majority of their programs select at least some of their trainees for their potential as researchers and nearly all encourage trainees to perform research. The more the selection process focuses on research, the greater the percentage of residents and fellows that participate in research during training. Nonetheless, only about one-third of residents and half of the fellows perform and publish research. Only half the programs offer formal research seminars and few trainees opt for additional research training. These results may relate to the relatively small percentage of faculty performing prospective clinical and laboratory research. These findings are disappointing in the light of previous results suggesting that performing research, publication, and formal research education during training correlate highly with the development of successful research careers. Chairmen could increase the likelihood of trainees choosing research careers and being successful in publishing research by providing early exposure to research experiences and providing formalized research training.

Academic Medical Centers↗
PubMed1990

Biodistribution and clearance of liposomal gadolinium-DTPA.

Gadolinium-DTPA (Gd-DTPA) liposomes have been studied previously as liver contrast agents and have been shown to improve the detection of hepatic metastases in rats. We synthesized 100-nm and 50-nm liposomes that encapsulated Gd-DTPA and did biodistribution and clearance studies in rats. Parallel magnetic resonance imaging (MRI) studies were also done. Biodistribution showed a prolonged blood pool phase for Gd-DTPA liposomes with a blood pool half-life of approximately 4 hours for the 100-nm liposomes. The highest uptake per gram of tissue was achieved by the spleen. Clearance of gadolinium from the liver and spleen showed a half-life of 3 to 4 days. The smaller 50-nm Gd-DTPA liposomes resulted in a longer blood pool phase and a higher delivery of gadolinium to the liver, bone marrow, and spleen. Imaging studies after intravenous (IV) administration of liposomal Gd-DTPA showed organ enhancement that paralleled the data on biodistribution studies, with appreciable hepatic enhancement at doses as low as 0.025 mm/kg of liposomal Gd-DTPA.

Animals↗
PubMed1990

Microvascular changes in rabbit kidneys after extracorporeal shock wave treatment.

Concerns about the safety of extracorporeal shock wave lithotripsy include the risk of vascular damage and the genesis of hypertension. We evaluated gross specimens and barium microangiograms of the right kidneys of 14 rabbits exposed to shock waves; the untreated left kidneys served as controls. Six rabbits were assessed immediately after shock wave treatment, whereas the other eight rabbits had the same procedure 3 months later. All six acute phase animals showed microangiographic changes indicative of shock wave trauma, including cortical, subcapsular, and medullary extravasation of barium and patchy loss of efferent vessels. No significant vascular abnormalities were seen in the control kidneys. All kidneys treated from the animals that had delayed microangiography showed macroscopic evidence of fibrotic capsular thickening and parenchymal scarring. Microscopically, there was crowding of glomeruli and areas of avascularity. In this model, shock waves damaged the cortical circulation and resulted in persistent alterations of the microvasculature that potentially could be responsible for the abnormal secretion of renin.

Animals↗
PubMed1990

Detection of breast abnormalities on teleradiology transmitted mammograms.

The authors conducted an observer performance study to compare breast lesion detection of conventional mammography (CM) with teleradiology (TE) transmitted mammograms. One hundred four abnormal, single-projection mammographic images were transmitted by teleradiology. Abnormalities included 11 cases with skin thickening or retraction, 48 cases with microcalcifications, and 52 with parenchymal masses. The CM and TE images were reviewed by four mammographers who indicated the type and location of abnormalities and a level of confidence for their diagnostic decisions. For each of three detection tasks--skin and nipple abnormalities, microcalcifications, and masses--receiver operating characteristic curve analysis was performed for individual readers and all readers as a group. For detecting skin and nipple abnormalities, readers performed significantly better with CM than with TE (z = 2.05, P = less than 0.04). However, no significant differences were found among readers for detection of either microcalcifications or masses. Further improvements in hardware and imaging parameters may improve detection of soft tissue abnormalities. Further evaluation is necessary to determine whether teleradiology might be applicable to breast cancer screening.

Breast Neoplasms↗
PubMed1990

Influences affecting radiologists' choices of academic or private practice careers.

The authors surveyed 5,000 practicing radiologists and 3,000 individuals currently in radiology training to determine the aspects of their backgrounds, education, training, and attitudes that most affected their career decisions. The choice of academic radiology was associated with receiving medical school education or radiology training at an institution ranking among the 20 with the most federal grant funding, publishing research articles, and participating in a variety of interpersonal research experiences during radiology training. Academic radiologists were more likely to choose their careers because of their interests, aptitudes, and greater concern for the value of doing research. Private practitioners rated family obligations, leisure time, and level of personal income as more significant influences on their career choices. Programs interested in training more academic radiologists should reconsider how they select trainees and provide an appropriate research environment during training.

Adult↗
PubMed1990

Mammography-guided stereotactic fine-needle aspiration cytology of nonpalpable breast lesions: prospective comparison with surgical biopsy results.

We assessed the usefulness of fine-needle aspiration cytology (FNAC) in evaluating nonpalpable breast abnormalities by prospectively performing stereotactic mammography-guided FNAC on 100 women undergoing surgical excisional biopsy. Mammographic and cytologic diagnoses, on a scale of 1 (benign) to 4 (malignant), were assigned for each case and compared with the surgical pathologic diagnosis. Sensitivity and specificity were examined at different diagnostic cutoff points for regarding a mammographic or cytologic diagnosis as positive or negative. Of the 100 breast biopsy specimens, 70 were benign and 30 were malignant. For both mammography and FNAC, the optimal diagnostic cutoff point was between diagnosis 2 (mammography, probably benign; cytology, atypical) and 3 (mammography and cytology both suspicious for malignancy). At this cutoff point, FNAC had a sensitivity of 0.77 and specificity of 1.00, vs 0.73 sensitivity and 0.79 specificity for mammography. Pearson coefficient analysis revealed significant correlations between both mammographic and FNAC diagnoses and surgical pathology (p less than .001 for both). Our results suggest that use of mammography-guided FNAC may reduce the number of breast biopsies performed for benign lesions.

Adult↗
PubMed1989

Clinical assessment of phosphor-plate computed radiography: equipment, strategy, and methods.

Initial experiences with a medical innovation project promise future applicability. Scientific assessment of the innovation usually points out deficiencies that must be overcome before optimal, widespread use of the technology is feasible. This presentation details the equipment, strategy, and methodological principles used at the University of Arizona in assessing the clinical use of computed radiography based on using phosphor plates as the X-ray receptor. The focus of this research has been to evaluate the applicability of computed radiography to clinical indications which might test potential weaknesses or virtues of the technology. We present examples of experiments that illustrate the general principles described.

Humans↗
PubMed1989

Factors influencing radiologists to choose research careers.

The future of radiology is threatened by the paucity of competent researchers who are radiologists. To determine what influences are most important in selecting and training potential radiology researchers, we conducted a survey of 5000 practicing radiologists, including all members of the Association of University Radiologists. We also surveyed 3000 randomly selected radiology trainees. A research career was empirically defined as 20% or more of a radiologist's time being involved with research. Response to the practicing radiologists and radiology trainees surveys was 28% and 19%, respectively. Radiologists who attended medical school or trained in radiology at an institution among the top 20 for research funding more frequently chose careers in research than those who matriculated and trained elsewhere. Publishing at least one research article, having a dedicated radiology research fellowship, having access to grant funds, and using computers during medical school or radiology training were factors typifying radiologists who chose research careers. Research radiologists were more concerned about the value of performing research and less concerned about personal income than those choosing careers not focusing on research. These results suggest that it might be possible to select radiology trainees who are more likely to become researchers based on their backgrounds and attitudes. An appropriate milieu during training enhances the likelihood of radiologists choosing research careers.

Career Choice↗
PubMed1989

Factors influencing the success of academic radiologists in publishing research.

To guide changes that might improve radiologists' research productivity, we surveyed 1400 members of the Association of University Radiologists. We evaluated the impact of influences related to background, education, training, attitudes, and practice environment on 558 respondents' frequency of research publication. Attending medical school, obtaining radiology training, and practicing at an institution among the 20 with the highest amount of research funding was associated with the highest research productivity in academic practice. Taking a radiology research fellowship, regularly attending research seminars, and association with a research mentor during training were also associated with higher career productivity. Virtually all aspects of the academic practice milieu, and particularly having time set aside for research, were significant influences on radiologists' frequency of publication. Men published research more frequently than women. This phenomenon appears related to women being afforded fewer research experiences during radiology training and a greater concern on the part of women about obstacles that hinder their doing research. These data might be employed to guide changes that would improve the selection and nurturing of individuals likely to be productive in research.

Attitude of Health Personnel↗